Medication Therapy in

Ambulatory Medical Care:

United States, 2003–04

Series 13, Number 163 December 2006
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Suggested citation

Raofi S, Schappert SM. Medication therapy in ambulatory medical care:

United States, 2003–04. National Center for Health Statistics. Vital Health Stat

13(163). 2006.

Library of Congress Cataloging-in-Publication Data

Raofi, Saeid.

Medication therapy in ambulatory medical care : United States, 2003–04.

p. ; cm. — (DHHS publication; no. (PHS) 2007–1734) (Vital and health

statistics. Series 13, Data from the National Health Care Survey; no. 163)

By Saeid Raofi and Susan M. Schappert.

‘‘November 2006.’’

Includes bibliographical references.

ISBN 0–8406–0610–9

1. Drug utilization—United States—Statistics. 2. Ambulatory medical care—

United States—Statistics. I. Schappert, Susan M. II. National Center for Health

Statistics (U.S.) III. Title. IV. Series. V. Series: Vital and health statistics. Series

13, Data from the National Health Survey; no. 163.

[DNLM: 1. Drug Therapy—utilization—United States. 2. Ambulatory

Care—statistics & numerical data—United States. W2 A N148vm no.163 2006]

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Series 13, Number 163

Medication Therapy in

Ambulatory Medical Care:

United States, 2003–04

Data From the National Health

Care Survey

U.S. DEPARTMENT OF HEALTH AND HUMAN SERVICES

Centers for Disease Control and Prevention

National Center for Health Statistics

Hyattsville, Maryland

December 2006

DHHS Publication No. (PHS) 2007-1734
National Center for Health Statistics

Edward J. Sondik, Ph.D., Director

Jennifer H. Madans, Ph.D., Acting Co-Deputy Director

Michael H. Sadagursky, Acting Co-Deputy Director

Jennifer H. Madans, Ph.D., Associate Director for Science

Jennifer H. Madans, Ph.D., Acting Associate Director for

Planning, Budget, and Legislation

Michael H. Sadagursky, Associate Director for

Management and Operations

Lawrence H. Cox, Ph.D., Associate Director for Research

and Methodology

Margot A. Palmer, Director for Information Technology

Margot A. Palmer, Acting Director for Information Services

Linda T. Bilheimer, Ph.D., Associate Director for Analysis

and Epidemiology

Charles J. Rothwell, M.S., Director for Vital Statistics

Jane E. Sisk, Ph.D., Director for Health Care Statistics

Jane F. Gentleman, Ph.D., Director for Health Interview

Statistics

Clifford L. Johnson, Director for Health and Nutrition

Examination Surveys

Division of Health Care Statistics

Jane E. Sisk, Ph.D., Director

Robin Remsburg, Dr.N., Deputy Director

Catharine W. Burt, Ed.D., Chief, Ambulatory Care Statistics

Branch

Charles Adams, Chief, Technical Services Branch
Contents

Abstract ................................................................................................ 1

Introduction ............................................................................................. 1

Methods ................................................................................................ 1

Results ................................................................................................... 3

Patient and Provider Characteristics.......................................................................... 3

Drug Characteristics ...................................................................................... 5

Time Comparisons........................................................................................ 7

Additional Information .................................................................................... 7

References ................................................................................................ 8

Appendix I............................................................................................... 30

Technical Notes ......................................................................................... 30

Appendix II ............................................................................................. 36

Definition of Terms...................................................................................... 36

Appendix III ............................................................................................. 38

Survey Instruments ...................................................................................... 38

Text Figures

1. Percent distribution of ambulatory care visits and drug mentions at ambulatory care visits, by setting type:

United States, 2003–04................................................................................ 4

2 Average rate of drug mentions at ambulatory care visits by setting type, according to patient age: United States,

2003–04............................................................................................ 4

3 Percentage of ambulatory care visits with one or more medications prescribed, provided, or continued, by patient race

and setting type: United States, 2003–04 ................................................................. 5

4. Annual rates of occurrence of the top 10 broad therapeutic classes of drugs provided, prescribed, or continued at

ambulatory care visits, United States: 2003–04 ............................................................ 6

5 Annual number of the 10 most frequently occurring generic substances in drugs prescribed, provided, or continued at

ambulatory care visits, United States: 2003–04 ............................................................ 7

6 Annual rate of drug mentions by ambulatory care setting: United States, 1993–94 and 2003–04 .................... 8

Detailed Tables

1. Annual number and percent distribution of ambulatory care visits by medication therapy, according to setting type:

United States, 2003–04................................................................................ 9

2. Annual number and percent distribution of drug mentions at ambulatory care visits by setting type, according to

selected patient and provider characteristics: United States, 2003–04.......................................... 11

3. Annual rate of drug mentions at ambulatory care visits, by setting type and selected patient and provider characteristics:

United States, 2003–04............................................................................... 13

4. Number and percent distribution of drug mentions at ambulatory care visits with corresponding standard errors, by

selected drug characteristics according to setting type: United States, 2003–04.................................. 15

5. Annual rate of broad therapeutic classes of drug mentions at ambulatory care visits, by setting type: United States,

2003–04........................................................................................... 17

6. Annual rate of the top 10 broad therapeutic classes of drugs provided, prescribed, or continued at ambulatory care

visits, with corresponding standard errors, by setting type: United States, 2003–04 .............................. 18

iii
7. Annual number and rate of therapeutic classes of drugs provided, prescribed, or continued at ambulatory care visits,

with percent distribution by setting type and corresponding standard errors: United States, 2003–04 ................ 19

8. Annual number and percent distribution of the 50 most frequently occurring generic-equivalents at ambulatory care

visits, with therapeutic class and corresponding standard errors: United States, 2003–04 .......................... 24

9. Annual number and percent distribution of the generic-equivalents most frequently provided, prescribed, or continued

at ambulatory care visits, by setting type, with corresponding standard errors: United States, 2003–04 .............. 25

10. Annual population rates for the top 20 specific therapeutic classes of drug mentions at ambulatory care visits, by

patient age and sex: United States, 2003–04.............................................................. 27

11. Annual population rates for the top 20 specific therapeutic classes of drug mentions at ambulatory care visits, by

selected patient and provider characteristics: United States, 2003–04.......................................... 28

12. Annual percent distribution and rate of the generic-equivalents most frequently provided, prescribed, or continued at

ambulatory care visits: United States, 1993–94 and 2003–04 ................................................ 29

Appendix Tables

I. Reclassification of physician specialty for use with National Ambulatory Medical Care Survey data ................ 33

II. Population estimates used in computing annual visit rates for the National Ambulatory Medical Care Survey and

National Hospital Ambulatory Medical Care Survey, by age, race, sex, and ethnicity: United States, 2003–04 ........ 34

III. Population estimates used in computing annual visit rates for the National Ambulatory Medical Care Survey and

National Hospital Ambulatory Medical Care Survey, by geographic region, metropolitan statistical area status, and

insurance status: United States, 2003–04 ................................................................ 35

iv
Objective

This report describes medication

therapy at visits to physician offices,

hospital outpatient departments, and

emergency departments in the United

States during 2003 and 2004.

Office-based care is further subdivided

into three categories—primary care,

surgical specialties, and medical

specialties.

Methods

Data from the 2003 and 2004

National Ambulatory Medical Care

Surveys (NAMCS) and National

Hospital Ambulatory Medical Care

Surveys (NHAMCS) were combined to

produce averaged annual estimates of

ambulatory medical care utilization.

Results

An estimated 1.9 billion drugs per

year were provided, prescribed, or

continued at ambulatory care visits in

the United States during 2003 and

2004. Two-thirds of the 1.1 billion

ambulatory care visits per year included

medication therapy. The rate was

highest at visits to medical specialists

(2.3 drugs per visit). The rate of drugs

per visit increased with patient age in

each ambulatory care setting.

Cardiovascular-renal was the class

of drugs most frequently cited at visits

to primary care physicians and medical

specialists. Pain relievers were the

drugs reported most often at hospital

emergency and outpatient department

visits. Of the 50 drugs most frequently

reported overall, three-quarters of them

were accounted for by six therapeutic

classes—pain relievers, cardiovascularrenal agents, respiratory tract drugs,

central nervous system drugs

(antianxiety agents and

antidepressants), hormonal agents, and

antimicrobials. Ibuprofen, aspirin,

atorvastatin calcium, acetaminophen,

and albuterol were the five most

frequently reported medications. From

1993 to 2004, the number of drugs

provided, prescribed, or continued per

visit increased for all settings.

Keywords: ambulatory care visits c

drug mentions c medication therapy c

pharmacotherapy c therapeutic

classification

Medication Therapy in

Ambulatory Medical Care:

United States, 2003–04

by Saeid Raofi, M.S., and Susan M. Schappert, M.A.,

Division of Health Care Statistics

Introduction

Medication therapy, or

pharmacotherapy, is the

predominant treatment

modality at ambulatory medical care

visits, and the cost of this treatment has

increased rapidly over the last decade.

In 2003, prescription drug expenditures

in the United States totaled $216.4

billion, an increase of $22.4 billion from

the previous year. The rate of increase

exceeded 10 percent in 2001, 2002, and

2003 (1). With such growth, an

assessment of the volume and

characteristics associated with

medication therapy at ambulatory health

care visits in the United States becomes

especially important.

This report describes medication

therapy at ambulatory medical care

visits in the United States across five

ambulatory care settings—primary care

offices, surgical specialty offices,

medical specialty offices, hospital

outpatient departments, and hospital

emergency departments. The data

presented are from the 2003 and 2004

National Ambulatory Medical Care

Surveys (NAMCS) and National

Hospital Ambulatory Medical Care

Surveys (NHAMCS), which were

combined to produce averaged annual

estimates of pharmacotherapy at

ambulatory medical care visits in the

United States. These surveys comprise

the ambulatory care component of the

National Health Care Surveys (NHCS),

conducted by the Centers for Disease

Control and Prevention’s National

Center for Health Statistics. NHCS

measures health care utilization across a

variety of health care providers. More

information can be found at

www.cdc.gov/nchs/nhcs.htm.

The report presents summary

statistics based on selected data items

common to NAMCS and NHAMCS, all

of which are related to medication

therapy. The annual summaries (2–7)

and the forthcoming series report focus

on general utilization data for 2003–04

(8) and contain an overview of the

medical care provided in each setting as

well as some general findings on

medication therapy. This report provides

greater detail on medication therapy

both within settings and across the

spectrum of ambulatory health care as a

whole.

Methods

This study is a secondary analysis

of data collected in the 2003 and

2004 NAMCS and NHAMCS.

The target universe for NAMCS

includes visits made in the United States

to the offices of nonfederally employed

physicians (excluding those in the

specialties of anesthesiology, pathology,

and radiology) who were classified by

the American Medical Association

(AMA) or the American Osteopathic

Association (AOA) as being primarily

engaged in office-based patient care.

Visits to private, nonhospital-based

clinics and health maintenance

organizations (HMOs) were within the

scope of the survey, but those that

occurred in federally operated facilities

and hospital-based outpatient

departments (OPD) were not. Telephone

contacts and visits made outside the

Page 1
Page 2 [ Series 13, No. 163

ambulatory care setting were not

sampled in either survey, although

limited information on the numbers of

such contacts was collected in NAMCS.

The target universe for NHAMCS is

in-person visits made to the OPDs and

emergency departments (EDs) of

nonfederal, short-stay hospitals

(hospitals with an average stay of less

than 30 days) or those whose specialty

is general (medical or surgical) or

children’s general, in the United States.

Only OPDs under the supervision of a

physician were within the scope of

NHAMCS. Clinics specializing in

ancillary services, treatment only (e.g.,

chemotherapy, dialysis, radiation,

physical therapy), and ambulatory

surgery were all out-of-scope for

NHAMCS. Visits from sampled OPD

clinics were combined to provide total

estimates for OPD utilization. This

includes clinics defined as general

medical care (57.8 percent of the

2003–04 total), pediatrics (14.0 percent),

general surgery (11.6 percent), obstetrics

and gynecology (8.2 percent), and all

other types (8.4 percent). (Surgery

clinics differ from ambulatory surgical

centers in OPDs in that the former

involve visits to surgeons for diagnosis

of problems requiring surgery and for

postsurgery followup. Ambulatory

surgery centers provide surgical

procedures that do not require

hospitalization.) EDs were defined as

those providing 24-hour emergency care.

Emergency care clinics that were open

less than 24 hours per day were

considered as part of the OPD.

The sampling frame for NHAMCS

is based on hospitals that were listed in

the April 1991 SMG Hospital Database.

The original sample has been updated

over the years to allow for inclusion of

hospitals that opened or whose

eligibility status had changed. The 2003

NHAMCS sampling frame was updated

using products of Verispan L.L.C.,

specifically, the ‘‘Healthcare Market

Index’’ and ‘‘Hospital Market Profiling

Solution.’’ These products were formerly

known as the SMG Hospital Database

and will be referred to as the Verispan

Hospital Database (VHD). For the 2003

NHAMCS only, an additional sample of

66 hospitals (identified as having an ED

and either located in nonmetropolitan

statistical areas or under proprietary

ownership) was selected from the 2002

VHD to provide more reliable estimates

for those categories. The 2004

NHAMCS frame was updated using the

2003 VHD.

A multistage probability sample

design is used in both surveys; the

designs are described elsewhere (9,10).

The combined 2003 and 2004 NAMCS

dataset contains 50,514 encounter

records from 2,779 in-scope physicians;

the combined NHAMCS dataset

contains 76,842 ED records and 66,275

OPD encounter forms from 428

participating hospitals in 2003 and 376

in 2004. Response rates for both surveys

ranged between 65 and 89 percent

across the 2-year period. See Appendix I

for additional information.

Because the estimates presented are

based on a sample rather than on the

entire universe of ambulatory visits, they

are subject to sampling variability. The

‘‘Technical Notes’’ in Appendix I

include an explanation of sampling

errors and guidelines for judging the

precision of the estimates, as well as

information on the tests of significance

used to establish differences among

survey estimates. Unless otherwise

noted, the determination of statistical

significance was based on the two-tailed

t-test. The Bonferonni inequality was

used to establish the critical value for

statistically significant differences (0.05

level of significance) based on the

number of possible comparisons within

a particular variable (or variables) of

interest.

Encounter data for each sampled

visit are collected using a one-page

questionnaire, the Patient Record form

(PRF). These forms are produced in

three different versions that have been

carefully designed for use in each

survey setting—physician offices

(NAMCS), and OPDs and EDs

(NHAMCS)—but which contain many

data items in common. NAMCS and

OPD PRFs are nearly identical, but the

ED PRF differs in ways appropriate to

that setting. These forms are used by

medical staff to record information

about patient visits. Definitions of terms

relating to the survey items are found in

Appendix II. The PRFs are shown in

Appendix III and should serve as a

reference for readers as they review the

survey findings presented in this

document.

In 2003 and 2004, pharmacotherapy

data were collected in item 9,

‘‘Medications & Injections’’ of the PRF,

and the same format was used in all

three settings. The question asks

respondents to list up to eight ‘‘Rx and

OTC medications, immunizations,

allergy shots, anesthetics, and dietary

supplements that were ordered, supplied,

administered, or continued during this

visit.’’ (Note: Rx is prescription; OTC is

over the counter.) Each entry of a

medication on the form is referred to as

a ‘‘drug mention’’ in NAMCS and

NHAMCS reports, and visits with at

least one drug mention are termed

‘‘drug visits.’’ The term, ‘‘prescribed,’’

as used in this report reflects the

broader definition stated above.

Drug mentions were coded

according to a coding system developed

at NCHS. A report describing the

method and instruments used to collect

and process drug information is

available (11). Additional sources,

including the American Drug Index,

Drug Topics Red Book, Facts and

Comparisons, and the National Drug

Code Directory, 1995 edition (NDC),

were used to identify and assign drug

characteristics for analytical purposes

(12–15). The NDC assigns therapeutic

classes for each drug using a two-tiered

system. There are 21 broad therapeutic

classes (2-digit level), and drugs are

assigned to subclasses (4-digit level)

within the broad classes. This report

presents therapeutic classes using the 2­

and 4-digit levels, depending upon the

table.

The presentation of drug mentions

in terms of their generic substances has

been changed for 2003–04 compared

with previous years of NAMCS and

NHAMCS reports. In the past,

frequency of mention estimates

combined single-ingredient agents with

mentions of the agent as an ingredient

in a combination drug. That is, a

preparation containing acetaminophen

and codeine was included both in the

count for acetaminophen and the count

for codeine in tables of drugs by their

generic components. This meant that it

was possible for the number of generic
Series 13, No. 163 [ Page 3

substances to exceed the number of

actual drug mentions. For this report

(with the exception of Figure 5, which

presents generic substances according to

the method just described), drugs

containing multiple ingredients are

presented in tables of generic substances

using entries that reflect combinations of

ingredients. These entries are termed

‘‘generic equivalents’’ in the text. For

example, a preparation containing only

acetaminophen and codeine would no

longer be listed under each separate

ingredient, but would appear in the table

under a new entry for ‘‘acetaminophen

with codeine.’’

Also of note is the fact that, since

2002, up to three therapeutic classes can

be coded for each drug mention in

NAMCS and NHAMCS data. Therefore,

summary statistics in tables that show

mentions by therapeutic class of drugs

can exceed the total number of drug

mentions.

Table 11 compares the drugs most

frequently provided, prescribed, or

continued at NAMCS and NHAMCS

visits in 1993–94 with those in

2003–04. It should be noted that,

because only five drugs could be coded

per visit during 1993–94, only the first

five (out of a possible eight) drugs listed

on the visit records for 2003–04 were

used for the time comparison.

Additional information about the

analysis and presentation of drug

estimates is shown in Appendix I.

The PRF item, ‘‘Primary expected

source of payment for this visit,’’ is

used to define the method of payment

expected by the provider for the visit. It

includes the categories of private

insurance, Medicare, Medicaid, Worker’s

Compensation, self-pay, no charge,

other, and unknown. For this report,

self-pay and no charge were combined

to yield estimates of uninsured visits.

Worker’s Compensation, other, and

unknown response categories were

combined into a residual category called

‘‘Other.’’ Visit rates by expected pay

source use population estimates of

health insurance from the 2003–04

National Health Interview Surveys for

the denominator (16,17). The numerator

used in calculating rates for the

no-insurance group comes from the PRF

self-pay and no charge categories.

Although not all uninsured visits are

made by uninsured persons, the number

of uninsured persons is used to calculate

rates of uninsured visits. For NAMCS

and NHAMCS self-pay and no charge

visits (uninsured visits), there is no

expectation of third-party payers

covering the cost.

Visits to office-based physicians,

which account for 82 percent of the

ambulatory care visits discussed in this

report, were divided into three settings.

This classification was suggested by the

American Medical Association (18) and

is based on physicians’ self-designated

practice specialty to better portray the

diversity of care that occurs in physician

offices. Table I in Appendix I shows the

specialties used to define each category.

Self-designated practice specialty is

collected from AMA and AOA as part

of the initial sampling process and is

confirmed with the physician at the time

of the survey induction interview. For

tabulation purposes, doctors of

osteopathy were grouped with doctors of

medicine according to specialty.

In this report, the terms, ‘‘visits to

office-based physicians’’ and ‘‘visits to

physician offices’’ are used

interchangeably, as are the terms ‘‘visits

to specialists,’’ ‘‘visits to specialty

offices,’’ and ‘‘visits to specialties.’’

Some tables in this report present

data on population-based rates of drug

mentions at ambulatory care visits. With

the exception of the expected source of

payment, the population figures used in

calculating these rates were special

tabulations of the civilian

noninstitutionalized population of the

United States, developed by the

Population Division, U.S. Census

Bureau, from the July 1, 2003, and July

1, 2004, set of state population estimates

by age, sex, race, and Hispanic origin.

These estimates are based on census

2000 data. Population figures are shown

in Tables II and III in Appendix I.

The U.S. Census Bureau was

responsible for data collection for both

surveys. Constella Group, formerly

Analytic Sciences, Inc., Durham, North

Carolina, performed processing

operations and medical coding. As part

of the quality assurance procedure, a

10 percent quality control sample of

survey records was independently

processed. Error rates (which include

coding and keying) ranged between 0.0

and 1.5 percent depending on the survey

and item.

Results

This report contains detailed data

on medication therapy at

ambulatory care visits by setting

type (Table 1), patient and provider

characteristics (Tables 2,3), drug

characteristics (Tables 4–7), ranked

generic substances (Tables 8,9) and

population-based prescribing rates for

therapeutic classes of drugs

(Tables 10,11). To examine changes over

time, comparisons of generic substances

used in 1993–94 and 2003–04 are

presented in Table 12. Highlights of

information found in the tables are

shown below.

Patient and Provider

Characteristics

There was an annual average of 1.1

billion ambulatory care visits in 2003

and 2004. Primary care offices

accounted for the largest share

(48.0 percent of visits), followed by

medical specialty offices (17.6 percent)

and surgical specialty offices

(16.2 percent). About 10 percent of visits

were made to hospital emergency

departments, and 8.1 percent were made

to hospital OPDs (Figure 1). Two-thirds

of ambulatory care visits (66.4 percent)

included medication therapy (Table 1).

There were an estimated 1.9 billion

drug mentions per year in 2003 and

2004. One-half (50.1 percent) of all drug

mentions were accounted for by visits to

primary care physicians. Although

surgical specialties accounted for

16.2 percent of the visits, these visits

only accounted for 7.6 percent of total

drug mentions. In contrast, medical

specialty offices accounted for

17.6 percent of visits, but 22.9 percent

of drug mentions. Visits to hospital EDs

were responsible for 11.0 percent and

OPDs were responsible for 8.4 percent
Page 4 [ Series 13, No. 163

Emergency departments Emergency departments 

48.0% 

16.2% 

17.6% 

8.1% 

10.1% 

Surgical specialty 

offices 

Primary care 

offices 

Outpatient Outpatient

departments departments

Medical specialty Medical specialty offices 

offices 

Surgical specialty 

offices 

Primary care 

offices 

22.9% 50.1%

7.6% 

8.4% 

11.0% 

Visits Drug mentions 

Figure 1. Percent distribution of ambulatory care visits and drug mentions at ambulatory care visits, by setting type: United States,

2003–04

of the total drug mentions (Table 2,

Figure 1).

As shown in Table 3, the average

number of drug mentions per 100 visits

was not significantly different at visits

to primary care offices, OPDs, and EDs,

ranging between 183.0 and 190.9

mentions per 100 visits. The rate was

higher for visits to medical specialty

offices (227.7 drugs per 100 visits)

compared with primary care office

visits, but lower for surgical specialty

visits (82.4 drugs per 100 visits).

Drug mention rates (i.e., the number

of drug mentions per 100 visits)

increased in general with patient age,

both overall and within each ambulatory

care setting. The overall rate ranged

from 126.4 drugs per 100 visits by

patients under 15 years of age to 251.5

drugs per 100 visits by patients 75 years

and over (Figure 2). Drug mention rates

for males and females were not

significantly different, with one

exception. The drug mention rate was

higher for females (196.6 per 100 visits)

than males (184.1 per 100 visits) at ED

visits.

There were no significant

differences in drug mention rates by

race. However, at visits to medical

drugs (78.8 percent) than white patients (72.1 percent). These differences were

(72.6 percent) or Asian patients statistically significant (X2 = 7.26,

Primary care offices Surgical specialty offices

Medical specialty offices Outpatient departments

Emergency departments 

NOTE: All increases shown are significant (p<.05). 

0 

50 

100 

150 

200 

250 

300 

350 

Under 15 15–24 25–44 45–64 65–74 75

Patient age in years 

Number of mentions per 100 visits 

specialties, black patients had a higher Figure 2. Average rate of drug mentions at ambulatory care visits by setting type,

likelihood of receiving one or more according to patient age: United States, 2003–04
Series 13, No. 163 [ Page 5

p < 0.03) (Figure 3). There were no

significant differences in drug mention

rates by setting for Hispanic and

non-Hispanic persons.

The number of medications

mentioned per 100 visits was

significantly higher for visits where

Medicare was the primary expected

source of payment regardless of setting,

reflecting the age of the Medicare

population. In the medical specialty

setting, uninsured visits had a lower rate

of drug mentions (155.2 mentions per

100 visits) compared with private

insurance (205.4 mentions per 100

visits) and Medicaid visits (230.8

mentions per 100 visits). The rate was

not significantly different for private

insurance visits compared with Medicaid

visits.

Overall, there were no statistically

significant differences in drug mention

rates by geographic region. However,

surgical specialty visits in the West had

a higher drug mention rate (116.6

mentions per 100 visits) than such visits

in other regions. ED visits in the West

had a higher drug mention rate (220.7

mentions per 100 visits) than in either

the Northeast or the Midwest.

With the exception of visits to

primary care physicians, there were no

significant differences in drug mention

rates by setting for metropolitan

statistical areas (MSAs) and

nonmetropolitan statistical areas

(non-MSAs). In non-MSAs, the drug

mention rate at visits to primary care

physicians was 213.3 mentions per 100

visits compared with a rate of 177.7

mentions per 100 visits in MSAs.

Drug Characteristics

As shown in Table 4, the majority

(82.7 percent) of medications reported at

ambulatory care visits were prescription

drugs. Nonprescription preparations

accounted for 9.8 percent of mentions

overall, and 7.5 percent were of

undetermined status. Mentions of

nonprescription products and products of

White Black Asian

0 

10 

20 

30 

40 

50 

60 

70 

80 

Emergency 

departments 

Outpatient 

departments 

Medical 

specialty1 

offices 

Surgical 

specialty 

offices 

Primary 

care 

offices 

1

Differences are significant (p<.05). 

NOTE: Estimates for races other than white, black, and Asian are not shown because of small sample sizes. 

Percent of visits 

undetermined status were higher at visits

to EDs than at all other settings. The

former finding is likely related to the

frequent utilization at ED visits of

nonprescription pain relievers such as

acetaminophen, and the latter finding

may be related to the frequent utilization

of ibuprofen, which, in itself, can be

used in either an over-the-counter or

prescription strength. NAMCS and

NHAMCS do not collect route, dosage,

or regimen for medications listed on the

PRF, so those drugs that can take either

form (over the counter or prescription)

cannot be classified.

Table 4 also provides information

on federal control status. The Controlled

Substances Act, Title II of the

Comprehensive Drug Abuse Prevention

and Control Act of 1970, placed all

substances that are regulated under

existing federal law into one of five

schedules, based on the substance’s

medicinal value, harmfulness, and

potential for abuse or addiction.

Schedule I is reserved for the most

dangerous drugs that have no currently

accepted medical use in treatment in the

United States. Schedule II-V drugs all

have a currently accepted medical use

and decreasing potentials for abuse and

addiction, ranging from high (Schedule

II) to low (Schedule V). See Appendix

II for details.

Schedule II and III drugs accounted

for 4.5 percent of drug mentions overall.

ED visits included a significantly higher

proportion of schedule II drugs

(7.0 percent) and schedule III drugs

(6.3 percent) compared with all other

settings. This is probably related to the

preponderance of pain-relieving agents,

including narcotic analgesics. Schedule

IV drugs constituted 4.4 percent of drug

mentions in the medical specialty

setting. This was significantly higher

than the percentages in other settings,

which ranged from 2.4 to 3.4 percent.

Therapeutic class of drugs by

setting is shown in Table 5, using broad

classes (2-digit level of the NDC).

Cardiovascular-renal drugs had the

highest rate of utilization at medical

specialty offices with 37.4 occurrences

per 100 visits. This was significantly

higher than the rate for all other

Figure 3. Percentage of ambulatory care visits with one or more medications prescribed, settings, with the exception of primary

provided, or continued by patient race and setting type: United States, 2003–04 care offices (28.9 occurrences per 100
Page 6 [ Series 13, No. 163

visits). Pain relievers were utilized most

often at ED visits (64.7 occurrences per

100 visits), which was significantly

higher than the rate for all other

settings.

The top 10 broad therapeutic classes

(2-digit level of the NDC) are shown for

ambulatory care visits, in general, in

Figure 4. Eight of these classes are

among the top 10 therapeutic classes for

each setting (Table 6). These include

cardiovascular-renal, pain relief,

respiratory tract, central nervous system,

metabolic and nutrient agents, hormones

and hormonal agents, antimicrobials,

and gastrointestinal agents. Opthalmics

were among the top 10 at surgical

specialty visits, and otics were among

the top 10 at ED visits. Skin and

mucous membrane drugs were ranked

among the top 10 at each type of

physician office visit (primary care,

surgical specialty, and medical

specialty). Neurologics appeared among

the top 10 at medical specialty visits as

well as at OPD and ED visits. More

detailed data on therapeutic class of

drug mentions are shown in Table 7,

using the 4-digit therapeutic class codes

from the NDC. Nonsteroidal antiinflammatory drugs (NSAIDs) (57.5

mentions per 1,000 drug mentions) and

antidepressants (45.8 mentions per 1,000

drug mentions) were the top two

specific drug classes prescribed.

Figure 5 shows the 10 most

frequently occurring generic substances

in medications provided, prescribed, or

continued at ambulatory care visits

across all settings. As described

previously, occurrence, in this figure

only, is calculated as the sum of

mentions of single-ingredient agents

with mentions of the agent as an

ingredient in a combination drug.

Acetaminophen was the substance found

most frequently, with 91.1 million

mentions, reflecting 4.7 percent of total

drug mentions.

Drug mentions at ambulatory care

visits overall are shown by ranked

generic-equivalent substances in Table 8.

As noted earlier, this method produces

one generic-equivalent entry for each

drug and can be aggregated to the total

number of drug mentions. Ibuprofen was

the most frequently used substance

(2.1 percent of drug mentions), followed

by aspirin (2.0 percent) and atorvastatin

calcium (1.7 percent). When comparing

results from this table with those in

Figure 5, readers should note the

difference in methods used, which will

produce different results. For example,

NOTE: Based on the standard drug classification used in the National Drug Code Directory, 1995 edition (12). 

0 5 10 15 20 25 30 

Immunologics 

Skin/mucous 

membranes 

Gastrointestinals 

Hormones/hormonal 

mechanisms 

Metabolics/nutrients 

Antimicrobials 

Central nervous system 

Respiratory tract 

Cardiovascular-renal 

Relief of pain 

Number of occurrences per 100 visits 

Therapeutic class 

Figure 4. Annual rates of occurrence of the top 10 broad therapeutic classes of drugs

provided, prescribed, or continued at ambulatory care visits: United States, 2003–04

acetaminophen, when counted under its

use as both a single-ingredient drug and

a combination product, dominates the

list of most frequently occurring generic

substances in Figure 5, with an estimate

of 91.5 million, or 4.7 percent of all

drug mentions. When compared with

results from Table 8, readers will note

that acetaminophen as a singleingredient preparation accounts for

1.6 percent of total drug mentions. The

difference is related to the fact that

acetaminophen is often prescribed as

part of a combination product, and such

products (e.g., acetaminophen with

hydrocodone) are shown as separate

entries in Table 8.

The top 50 drugs were dominated

by six therapeutic classes, using the

2-digit NDC categories. These include

pain relievers (9 drugs in the top 50),

cardiovascular-renal drugs (6 drugs),

respiratory tract drugs (6 drugs), central

nervous system (6 drugs), hormones (6

drugs), and antimicrobials (5 drugs).

Albuterol was the most frequently

mentioned respiratory tract drug and

accounted for 1.5 percent of mentions

overall. Sertraline, used in the treatment

of depression and anxiety, was the most

frequently mentioned central nervous

system drug. Amoxicillin was the most

frequently mentioned antimicrobial drug

(1.3 percent of mentions), and

furosemide was the most frequently

mentioned cardiovascular agent. In the

hormonal class, levothyroxine was

mentioned most frequently, and

ibuprofen was the most frequently

mentioned pain reliever. Gastrointestinal

agents and metabolics and nutrients

were other classes with more than one

drug among the top 50.

Due to the diversity of vitamin

products and lack of accurate

information on the specific components

of many multivitamins, they were

excluded from Tables 8 and 9. This

group, as a whole, accounted for 49.8

million drug mentions (2.6 percent of all

drug mentions) across all settings in

2003–04.

Table 9 presents the top 10 drugs in

terms of their generic composition for

each ambulatory care setting. In

2003–04, the top three drugs cited at

visits to primary care physicians were

atorvastatin calcium (a cholesterol
Series 13, No. 163 [ Page 7

0 20,000 40,000 60,000 80,000 100,000 

Levothyroxine 

Fluticasone propionate 

Atorvastatin calcium 

Albuterol 

Hydrochlorothiazide 

Hydrocodone 

Amoxicillin 

Ibuprofen 

Aspirin 

Acetaminophen 

NOTE: Occurrence is the sum of the mentions of single-ingredient agents with mentions of the agent as an ingredient in a 

combination drug. Generic substance 

Number of occurrences in thousands 

Figure 5. Annual number of the 10 most frequently occurring generic substances in drugs

provided, prescribed, or continued at ambulatory care visits: United States, 2003–04

lowering agent), aspirin, and

amoxicillin. Among the top 10 drugs at

visits to primary care physicians were

three cardiovascular agents, three pain

relievers, and two antibiotics. Albuterol,

used in the control of asthma, and

levothyroxine, used to treat thyroid

disorders, were also present.

At visits to surgical specialists,

among the top 10 generic substances

were five pain relievers, three

ophthalmic agents, and two anesthetic

drugs. Prednisolone, acetaminophen with

hydrocodone, and latanprost, a glaucoma

medication, were listed most frequently.

Cardiovascular-renal drugs were

prominent at visits to medical specialty

offices, constituting 5 of the top 10

drugs in that setting. Aspirin was the

drug cited most frequently, and it

accounted for 2.7 percent of mentions.

Although it is classified in the NDC as

a nonnarcotic analgesic, aspirin therapy

is increasingly being used for the

prevention and management of heart

disease.

Pain relief agents, cardiovascular

drugs, antibiotics, and an asthma

medication were all among the top 10

drugs at OPD visits. Among the pain

relievers, a narcotic analgesic,

acetaminophen with hydrocodone, was

also present. At ED visits, pain relievers

dominated with 6 of the top 10 drugs;

acetaminophen with hydrocodone

accounted for 5.2 percent of mentions.

Taken together, the six pain relievers

account for 24.3 percent, or one-quarter

of ED drug mentions. Antibiotics,

cardiovascular drugs, and asthma

medication rounded out the list.

Table 10 presents population-based

prescribing rates for therapeutic classes

(using the more detailed 4-digit NDC

categories) of drugs provided, prescribed

or continued at ambulatory care visits

by patient age and sex. Occurrence rates

for each of the 20 most commonly

prescribed therapeutic classes of drugs

increased with patient age, with the

exception of vaccines and antisera. The

rates for antidepressants and for

vitamins and minerals for females were

significantly higher than corresponding

rates for males.

Table 11 presents population-based

prescribing rates for therapeutic classes

of drugs by patient race, expected

source of payment for the visit, and

MSA status. White persons had a much

higher rate of antidepressant mentions

than black persons, and black persons

had a higher rate of blood glucose

regulators. Persons whose expected

source of payment was Medicaid had

the highest rate of penicillin mentions

compared with those who had other

payment sources. Those defined as

uninsured had the lowest rate for all of

the top 20 therapeutic classes with the

exception of antidepressants, narcotic

analgesics, nonnarcotic analgesics, and

anticonvulsants. The mention rate for

vaccines was higher in MSAs than

non-MSAs.

Time Comparisons

To look at changes over time, drug

mention rates (number of mentions per

100 visits) for each ambulatory care

setting are compared for 1993–94 and

2003–04 in Figure 6. Because only five

drugs could be reported in 1993 and

1994, the number of drugs analyzed for

2003–04 in this figure only reflects the

first five listed on the PRF. In addition,

data for both sets of years reflect the

generic-equivalent method for displaying

drug data described in the ‘‘Methods’’

section. Rates were higher for all

settings in 2003–04 compared with

1993–94.

Further comparisons are shown in

Table 12, with the most frequently

mentioned generic substances in

1993–94 and 2003–04. Five of these

drugs were among the top 10 in both

time periods. However, aspirin use

increased, from 1.1 percent of total drug

mentions in 1993–94 to 1.8 percent of

total drug mentions in 2003–04, while

use of amoxicillin decreased. Estrogen

was no longer among the most

frequently mentioned drugs in 2003–04.

Additional Information

Ambulatory care visit and drug data

from NAMCS and NHAMCS are

available in a variety of formats

including CD-ROM and downloadable

data files accessed through the

Ambulatory Health Care Data homepage

on the Internet at http://www.cdc.gov/

nchs/namcs.htm. For additional

information concerning NAMCS and

NHAMCS data, contact the Ambulatory

Care Statistics Branch at

(301) 458–4600.
0 50 100 150 200 

Page 8 [ Series 13, No. 163

1993–94 

2003–04 

NOTE: All differences are significant (p<.05). 

Emergency departments 

Outpatient departments 

Medical specialty offices 

Surgical specialty offices 

Primary care offices 

Number of mentions per 100 visits 

Figure 6. Annual rate of drug mentions by ambulatory care setting: United States,

1993–94 and 2003–04

References

1.Hoffman JM, Vermeulen LC, Hunkler

RJ, Hontz KM. Projecting future drug

expenditure—2005. Am J Health-Syst

Pharm. 62 (2):149–67. 2005.

2.Hing E, Cherry D, Woodwell D.

National Ambulatory Medical Care

Survey: 2004 summary. Advance data

from vital and health statistics; no 374.

Hyattsville, MD: National Center for

Health Statistics. 2006.

3.McCaig LF, Nawar E. National

Hospital Ambulatory Medical Care

Survey: 2004 emergency department

summary. Advance data from vital and

health statistics; no 372. Hyattsville,

MD: National Center for Health

Statistics. 2006.

4.Middleton KM, Hing E. National

Hospital Ambulatory Medical Care

Survey: 2004 outpatient department

summary. Advance data from vital and

health statistics; no 373. Hyattsville,

MD: National Center for Health

Statistics. 2006.

5.Hing E, Cherry D, Woodwell D.

National Ambulatory Medical Care

Survey: 2003 summary. Advance data

from vital and health statistics; no 365.

Hyattsville, MD: National Center for

Health Statistics. 2005.

6.McCaig LF, Burt CW. National

Hospital Ambulatory Medical Care

Survey: 2003 emergency department

summary. Advance data from vital and

health statistics; no 358. Hyattsville,

MD: National Center for Health

Statistics. 2005.

7.Middleton KM, Hing E. National

Hospital Ambulatory Medical Care

Survey: 2003 outpatient department

summary. Advance data from vital and

health statistics; no 366. Hyattsville,

MD: National Center for Health

Statistics. 2005.

8.Schappert SM, Woodwell DA.

Ambulatory care visits to physician

offices, hospital outpatient departments,

and emergency departments: United

States, 2003–04. Vital Health Stat.

Hyattsville, MD: National Center for

Health Statistics. Forthcoming.

9.Bryant E, Shimizu I. Sample design,

sampling variance, and estimation

procedures for the National Ambulatory

Medical Care Survey. National Center

for Health Statistics. Vital Health Stat

2(108). 1988.

10.McCaig LF, McLemore T. Plan and

operation of the National Hospital

Ambulatory Medical Care Survey.

National Center for Health Statistics.

Vital Health Stat 1(24). 1994.

11.Koch H, Campbell W. The collection

and processing of drug information.

National Ambulatory Medical Care

Survey, 1980. National Center for

Health Statistics. Vital Health Stat

2(90). 1982.

12.Food and Drug Administration.

National Drug Code Directory, 1995

edition. Washington: Public Health

Service. 1995.

13.American Drug Index. Facts and

comparisons. St. Louis, MO.

14.Drug topics red book, pharmacy’s

fundamental reference. Montvale, NJ:

Medical Economics Company, Inc.

2005.

15.Drug facts and comparisons, loose-leaf

drug information service. St. Louis,

MO: Facts and Comparisons. 2005.

16.2003 National Health Interview Survey

downloadable public-use data files and

documentation available from:

ftp://ftp.cdc.gov/pub/Health_Statistics/

NCHS/Datasets/NHIS/2003/.

17.2004 National Health Interview Survey

downloadable public-use data files and

documentation available from:

ftp://ftp.cdc.gov/pub/Health_Statistics/

NCHS/Datasets/NHIS/2004/.

18.American Medical Association.

Physician characteristics and

distribution in the US, 2003–2004

edition. Chicago, IL. 2003.

19.Research Triangle Institute. SUDAAN

Language Manual, Release 9.0

Research Triangle Park, NC: Research

Triangle Institute. 2004.

20.2003–04 National Ambulatory Medical

Care Survey downloadable public-use

data file documentation available from:

ftp://ftp.cdc.gov/pub/Health_Statistics/

NCHS/Datasets/NAMCS/.

21.2003–04 National Hospital Ambulatory

Medical Care Survey downloadable

public-use data file documentation

available from: ftp://ftp.cdc.gov/pub/

Health_Statistics/NCHS/Datasets/

NHAMCS/.

22.Sirken MG, Shimizu I, French DK,

Brock DB. Manual on standards and

procedures for reviewing statistical

reports. Hyattsville, MD: National

Center for Health Statistics. 1990.

23.Office of Management and Budget.

Statistical Policy Directive No. 15,

Race and ethnic standards for federal

statistics and administrative reporting,

Federal Register; Part II:36873–946.

July 7, 1997.
Series 13, No. 163 [ Page 9

Table 1. Annual number and percent distribution of ambulatory care visits by medication therapy, according to setting type: United States,

2003–04

Primary Surgical Medical Hospital Hospital

Combined care specialty specialty outpatient emergency

Medication therapy settings offices offices offices departments departments

Number of visits in thousands

All visits ................... 1,110,285 533,239 179,569 195,632 89,786 112,060

Was medication therapy

provided or prescribed?

Yes ...................... 736,930 373,836 73,339 143,070 59,491 87,193

No ...................... 373,355 159,402 106,230 52,562 30,294 24,866

Number of medications

provided or prescribed

None ..................... 373,355 159,402 106,230 52,562 30,294 24,866

1 ....................... 285,641 148,522 37,957 47,900 21,269 29,993

2 ....................... 175,985 88,066 18,544 29,694 14,366 25,315

3 ....................... 97,771 48,388 7,720 18,737 8,056 14,870

4 ....................... 56,746 28,673 3,436 11,732 5,123 7,781

5 ....................... 35,947 17,869 2,088 9,034 3,244 3,712

6 ....................... 25,832 14,062 1,228 6,408 2,167 1,968

7 ....................... 16,836 8,386 740 5,019 1,438 1,252

8 ....................... 42,173 19,871 1,626 14,545 3,829 2,302

Medication therapy Standard error in thousands

All visits ................... 30,603 21,112 8,898 12,670 6,534 3,920

Was medication therapy

provided or prescribed?

Yes ...................... 20,834 15,165 4,407 9,604 4,659 3,263

No ...................... 13,873 8,988 5,993 4,928 2,304 946

Number of medications

provided or prescribed

None ..................... 13,873 8,988 5,993 4,928 2,304 946

1 ....................... 8,678 6,832 2,392 3,959 1,601 1,155

2 ....................... 5,415 4,318 1,364 2,194 1,183 990

3 ....................... 3,599 2,822 780 1,556 706 637

4 ....................... 2,467 1,902 541 1,082 452 389

5 ....................... 1,863 1,387 364 924 337 211

6 ....................... 1,629 1,336 229 753 272 149

7 ....................... 1,284 914 147 655 178 118

8 ....................... 3,449 2,327 313 1,996 684 313

Percent distribution

All visits ................... 100.0 100.0 100.0 100.0 100.0 100.0

Was medication therapy

provided or prescribed?

Yes ...................... 66.4 70.1 40.8 73.1 66.3 77.8

No ...................... 33.6 29.9 59.2 26.9 33.7 22.2

Number of medications

provided or prescribed

None ..................... 33.6 29.9 59.2 26.9 33.7 22.2

1 ....................... 25.7 27.9 21.1 24.5 23.7 26.8

2 ....................... 15.9 16.5 10.3 15.2 16.0 22.6

3 ....................... 8.8 9.1 4.3 9.6 9.0 13.3

4 ....................... 5.1 5.4 1.9 6.0 5.7 6.9

5 ....................... 3.2 3.4 1.2 4.6 3.6 3.3

6 ....................... 2.3 2.6 0.7 3.3 2.4 1.8

7 ....................... 1.5 1.6 0.4 2.6 1.6 1.1

8 ....................... 3.8 3.7 0.9 7.4 4.3 2.1

Standard error of percent

All visits ................... . . . . . . . . . . . . . . . . . .

See footnotes at end of table.
Page 10 [ Series 13, No. 163

Table 1. Annual number and percent distribution of ambulatory care visits by medication therapy, according to setting type: United States,

2003–04—Con.

Primary Surgical Medical Hospital Hospital

Combined care specialty specialty outpatient emergency

Medication therapy settings offices offices offices departments departments

Was medication therapy

provided or prescribed? Standard error of percent

Yes ...................... 0.7 1.1 1.5 1.7 1.3 0.6

No ...................... 0.7 1.1 1.5 1.7 1.3 0.6

Number of medications

provided or prescribed

None ..................... 0.7 1.1 1.5 1.7 1.3 0.6

1 ....................... 0.4 0.7 0.8 1.2 0.7 0.5

2 ....................... 0.3 0.4 0.6 0.6 0.6 0.3

3 ....................... 0.2 0.4 0.4 0.5 0.4 0.2

4 ....................... 0.2 0.3 0.3 0.4 0.3 0.2

5 ....................... 0.1 0.2 0.2 0.4 0.3 0.1

6 ....................... 0.1 0.2 0.1 0.3 0.2 0.1

7 ....................... 0.1 0.2 0.1 0.3 0.2 0.1

8 ....................... 0.3 0.4 0.2 0.9 0.6 0.3

...Category not applicable.

NOTES: Numbers may not add to totals due to rounding. Figures are annual averages.
Series 13, No. 163 [ Page 11

Table 2. Annual number and percent distribution of drug mentions at ambulatory care visits by setting type, according to selected patient

and provider characteristics: United States, 2003–04

Primary Surgical Medical Hospital Hospital

Combined care specialty specialty outpatient emergency

Characteristic settings offices offices offices departments departments

Number of mentions in thousands

All drug mentions .................. 1,947,870 975,895 147,946 445,540 164,578 213,909

Patient age

Under 15 years ................... 241,084 146,852 5,387 26,317 27,698 34,830

Under 1 year ................... 43,626 32,093 *262 *838 5,020 5,412

1–4 years ..................... 79,213 49,127 1,663 *5,530 9,107 13,786

5–14 years..................... 118,244 65,632 3,461 19,949 13,571 15,632

15–24 years ..................... 120,800 53,850 4,983 20,580 12,903 28,484

25–44 years ..................... 364,590 167,024 22,377 73,861 37,119 64,209

45–64 years ..................... 597,672 298,796 48,258 150,498 52,387 47,732

65–74 years ..................... 279,779 135,358 27,952 81,495 18,997 15,977

75 years and over ................. 343,945 174,016 38,989 92,789 15,474 22,677

Patient sex

Female ........................ 1,148,849 599,064 81,696 248,689 100,537 118,863

Male .......................... 799,021 376,832 66,250 196,852 64,041 95,046

Patient race1

White ......................... 1,614,647 817,980 128,031 387,891 119,991 160,755

Black or African American ............. 249,623 113,179 13,167 40,478 36,729 46,071

Asian ......................... 64,623 35,103 5,291 *14,601 5,299 4,328

Native Hawaiian or other Pacific Islander . . . 6,838 4,223 *591 * 493 850

American Indian or Alaska Native ........ 6,738 *2,314 *579 *1,510 902 1,434

More than one race reported ........... 5,400 3,097 * * *1,164 472

Patient ethnicity1

Hispanic or Latino.................. 202,480 107,021 13,798 30,719 24,252 26,689

Not Hispanic or Latino ............... 1,745,390 868,874 134,148 414,821 140,326 187,220

Primary expected source of payment

Private insurance .................. 920,614 515,199 66,738 204,730 57,421 76,526

Medicare ....................... 570,885 269,288 56,782 169,850 34,124 40,841

Medicaid ....................... 243,226 109,263 7,629 32,284 48,582 45,469

Uninsured....................... 105,732 45,141 10,798 20,776 10,175 18,841

Other ......................... 107,413 37,004 6,000 17,900 14,277 32,233

Geographic region of provider

Northeast ....................... 393,710 192,292 25,339 86,304 49,587 40,187

Midwest ........................ 438,332 227,202 25,579 94,034 45,141 46,376

South ......................... 698,911 344,673 53,410 166,881 50,642 83,305

West .......................... 416,917 211,728 43,618 98,322 19,208 44,042

MSA2 status of provider

MSA .......................... 1,664,627 807,305 132,188 413,631 131,330 180,173

Not MSA ....................... 283,242 168,590 15,758 31,909 *33,249 33,736

Percent distribution

All visits ........................ 100.0 50.1 7.6 22.9 8.4 11.0

Patient age

Under 15 years ................... 100.0 60.9 2.2 10.9 11.5 14.4

Under 1 year ................... 100.0 73.6 0.6 1.9 11.5 12.4

1–4 years ..................... 100.0 62.0 2.1 7.0 11.5 17.4

5–14 years..................... 100.0 55.5 2.9 16.9 11.5 13.2

15–24 years ..................... 100.0 44.6 4.1 17.0 10.7 23.6

25–44 years ..................... 100.0 45.8 6.1 20.3 10.2 17.6

45–64 years ..................... 100.0 50.0 8.1 25.2 8.8 8.0

65–74 years ..................... 100.0 48.4 10.0 29.1 6.8 5.7

75 years and over ................. 100.0 50.6 11.3 27.0 4.5 6.6

See footnotes at end of table.
Page 12 [ Series 13, No. 163

Table 2. Annual number and percent distribution of drug mentions at ambulatory care visits by setting type, according to selected patient

and provider characteristics: United States, 2003–04—Con.

Primary Surgical Medical Hospital Hospital

Combined care specialty specialty outpatient emergency

Characteristic settings offices offices offices departments departments

Patient sex Percent distribution

Female ........................ 100.0 52.1 7.1 21.6 8.8 10.3

Male .......................... 100.0 47.2 8.3 24.6 8.0 11.9

Patient race1

White ......................... 100.0 50.7 7.9 24.0 7.4 10.0

Black or African American ............. 100.0 45.3 5.3 16.2 14.7 18.5

Asian ......................... 100.0 54.3 8.2 22.6 8.2 6.7

Native Hawaiian or other Pacific Islander . . . 100.0 61.8 8.6 * 7.2 12.4

American Indian or Alaska Native ........ 100.0 34.3 8.6 22.4 13.4 21.3

More than one race reported ........... 100.0 57.3 * * 21.6 8.7

Patient ethnicity1

Hispanic or Latino.................. 100.0 52.9 6.8 15.2 12.0 13.2

Not Hispanic or Latino ............... 100.0 49.8 7.7 23.8 8.0 10.7

Primary expected source of payment

Private insurance .................. 100.0 56.0 7.2 22.2 6.2 8.3

Medicare ....................... 100.0 47.2 9.9 29.8 6.0 7.2

Medicaid ....................... 100.0 44.9 3.1 13.3 20.0 18.7

Uninsured....................... 100.0 42.7 10.2 19.7 9.6 17.8

Other ......................... 100.0 34.5 5.6 16.7 13.3 30.0

Geographic region of provider

Northeast ....................... 100.0 48.8 6.4 21.9 12.6 10.2

Midwest ........................ 100.0 51.8 5.8 21.5 10.3 10.6

South ......................... 100.0 49.3 7.6 23.9 7.2 11.9

West .......................... 100.0 50.8 10.5 23.6 4.6 10.6

MSA2 status of provider

MSA .......................... 100.0 48.5 7.9 24.8 7.9 10.8

Not MSA ....................... 100.0 59.5 5.6 11.3 11.7 11.9

* Figure does not meet standard of reliability or precision.

1

Persons of Hispanic or Latino origin may be of any race or combination of races. Similarly, the category ‘‘Not Hispanic or Latino’’ refers to all persons who are not of Hispanic or Latino origin,

regardless of race. Starting with data year 1999, race-specific estimates have been tabulated according to the 1997 standards for federal data on race and Hispanic or Latino origin and are not strictly

comparable with estimates for earlier years. See Appendix I for details.

2

MSA is Metropolitan Statistical Area.

NOTES: Numbers may not add to totals due to rounding. Figures are annual averages.
Series 13, No. 163 [ Page 13

Table 3. Annual rate of drug mentions at ambulatory care visits, by setting type and selected patient and provider characteristics:

United States, 2003–04

Primary Surgical Medical Hospital Hospital

Combined care specialty specialty outpatient emergency

Characteristic settings offices offices offices departments departments

Number of mentions per 100 visits1

All visits ........................ 175.4 183.0 82.4 227.7 183.3 190.9

Patient age

Under 15 years ................... 126.4 123.5 42.7 174.3 136.4 146.1

Under 1 year ................... 127.4 127.5 *29.5 *110.6 142.1 138.8

1–4 years ..................... 130.9 127.1 49.1 *172.3 142.6 155.3

5–14 years..................... 123.2 119.2 41.6 179.1 130.6 141.3

15–24 years ..................... 120.7 109.9 51.7 160.0 120.2 159.7

25–44 years ..................... 143.3 133.2 67.8 182.3 161.8 197.5

45–64 years ..................... 196.2 218.8 82.4 229.5 230.6 224.6

65–74 years ..................... 226.1 274.0 91.8 271.1 266.9 239.0

75 years and over ................. 251.5 322.2 110.5 294.4 259.6 227.9

Patient sex

Female ........................ 176.3 181.8 83.1 229.1 183.5 196.6

Male .......................... 174.2 185.1 81.5 226.1 182.9 184.1

Patient race2

White ......................... 174.4 183.9 80.6 224.9 182.1 191.8

Black or African American ............. 183.9 185.3 90.2 262.1 185.9 185.6

Asian ......................... 169.9 163.5 106.5 *218.3 188.9 206.8

Native Hawaiian or other Pacific Islander . . . 189.3 196.0 *136.4 * 167.7 199.4

American Indian or Alaska Native ........ 193.2 *172.3 *121.1 *289.2 196.0 209.3

More than one race reported ........... 146.2 126.6 * * *202.4 197.4

Patient ethnicity2

Hispanic or Latino.................. 160.0 160.6 86.2 206.4 166.2 185.0

Not Hispanic or Latino ............... 177.4 186.2 82.0 229.5 186.6 191.8

Primary expected source of payment

Private insurance .................. 157.7 160.3 75.7 205.4 168.4 189.4

Medicare ....................... 240.6 290.3 101.3 294.4 261.4 230.5

Medicaid ....................... 172.0 163.6 75.3 230.8 186.4 186.0

Uninsured....................... 151.1 168.1 58.5 155.2 151.5 180.4

Other ......................... 138.0 149.6 72.3 162.9 142.3 162.1

Geographic region of provider

Northeast ....................... 173.4 188.5 71.3 205.1 203.2 174.4

Midwest ........................ 181.5 196.7 66.9 260.9 175.9 178.3

South ......................... 167.3 172.6 78.1 213.1 178.3 193.5

West .......................... 186.3 182.6 116.6 250.8 169.7 220.7

MSA3 status of provider

MSA .......................... 172.9 177.7 82.7 229.4 176.6 192.0

Not MSA ....................... 191.7 213.3 79.5 208.6 *215.6 185.1

Standard error of rate

All visits ........................ 4.6 7.0 4.8 12.2 8.3 4.1

Patient age

Under 15 years ................... 3.2 4.1 4.9 14.1 5.3 3.6

Under 1 year ................... 5.7 7.5 9.0 41.8 8.4 4.4

1–4 years ..................... 4.1 5.7 7.1 20.6 6.2 4.8

5–14 years..................... 3.5 4.1 5.1 13.1 6.8 3.5

15–24 years ..................... 2.8 4.7 4.3 7.5 5.2 3.0

25–44 years ..................... 3.6 5.3 5.4 9.0 7.3 3.7

45–64 years ..................... 6.3 10.8 5.3 12.8 12.5 6.0

65–74 years ..................... 8.3 13.6 6.7 19.6 18.9 9.8

75 years and over ................. 10.2 17.8 8.8 21.7 23.8 10.4

See footnotes at end of table.
Page 14 [ Series 13, No. 163

Table 3. Annual rate of drug mentions at ambulatory care visits, by setting type and selected patient and provider characteristics:

United States, 2003–04—Con.

Primary Surgical Medical Hospital Hospital

Combined care specialty specialty outpatient emergency

Characteristic settings offices offices offices departments departments

Patient sex Standard error of rate

Female ........................ 5.0 7.6 5.3 13.1 8.9 4.7

Male .......................... 4.7 7.5 4.8 12.9 8.2 3.6

Patient race2

White ......................... 4.8 7.5 4.8 12.1 10.1 4.2

Black or African American ............. 7.2 11.9 8.3 19.6 7.4 5.0

Asian ......................... 14.1 20.3 18.6 36.1 26.0 10.5

Native Hawaiian or other Pacific Islander . . . 14.8 25.9 30.1 * 19.7 11.7

American Indian or Alaska Native ........ 18.1 28.9 26.4 69.9 22.6 20.7

More than one race reported ........... 12.8 15.4 * * 18.2 20.0

Patient ethnicity2

Hispanic or Latino.................. 7.4 15.6 11.5 24.6 9.2 5.0

Not Hispanic or Latino ............... 4.9 7.0 4.7 12.1 9.2 4.3

Primary expected source of payment

Private insurance .................. 4.6 6.2 4.7 11.1 9.7 3.7

Medicare ....................... 9.0 16.0 7.5 19.8 16.4 9.5

Medicaid ....................... 5.7 9.5 7.9 21.6 9.6 4.7

Uninsured....................... 5.1 8.9 12.3 11.7 8.7 2.8

Other ......................... 5.9 11.1 10.6 18.3 6.7 5.2

Geographic region of provider

Northeast ....................... 12.9 17.1 8.7 27.7 22.4 8.7

Midwest ........................ 8.5 13.5 6.2 27.4 13.2 5.8

South ......................... 7.1 11.2 7.8 17.3 9.2 7.3

West .......................... 9.1 14.4 13.8 30.0 16.0 10.4

MSA3 status of provider

MSA .......................... 5.0 7.7 5.2 12.7 6.8 4.2

Not MSA ....................... 11.8 14.3 7.6 35.2 32.1 12.2

* Figure does not meet standard of reliability or precision.

1

Number of drug mentions divided by total number of visits multiplied by 100.

2

Persons of Hispanic or Latino origin may be of any race or combination of races. Similarly, the category ‘‘Not Hispanic or Latino’’ refers to all persons who are not of Hispanic or Latino origin,

regardless of race. Starting with data year 1999, race-specific estimates have been tabulated according to the 1997 standards for federal data on race and Hispanic or Latino origin and are not strictly

comparable with estimates for earlier years. See Appendix I for details.

3

MSA is Metropolitan Statistical Area.

NOTE: Figures are annual averages.
Series 13, No. 163 [ Page 15

Table 4. Number and percent distribution of drug mentions at ambulatory care visits with corresponding standard errors, by selected drug

characteristics according to setting type: United States, 2003–04

Primary Surgical Medical Hospital Hospital

Combined care specialty specialty outpatient emergency

Characteristic settings offices offices offices departments departments

All drug mentions ............. 1,947,870 975,895 147,946 445,540 164,578 213,909

Prescription status Number of mentions in thousands

Prescription ................. 1,611,601 818,055 122,314 379,071 132,797 159,363

Non-prescription1 ............. 191,145 91,188 14,268 35,288 19,523 30,877

Undetermined status ........... 145,124 66,652 11,364 31,181 12,258 23,669

Federal control status2

Schedule II ................. 43,513 13,569 1,909 9,230 3,921 14,884

Schedule III................. 44,801 18,633 4,799 4,750 3,077 13,543

Schedule IV ................ 60,154 24,764 3,557 19,482 5,049 7,301

Schedule V ................. 7,058 4,700 * 1,018 566 671

No control.................. 1,724,512 885,181 131,296 388,161 147,682 172,193

Undetermined ............... 67,832 29,049 6,282 22,900 4,283 5,317

Standard error in thousands

All drug mentions ............. 72,398 50,268 10,949 36,163 15,408 9,218

Prescription status

Prescription ................. 59,393 42,136 9,218 30,251 12,535 6,904

Non-prescription1 ............. 8,957 6,267 1,465 3,825 1,986 1,496

Undetermined status ........... 7,549 4,875 1,081 4,039 1,124 1,153

Federal control status2

Schedule II ................. 2,031 1,173 352 1,066 602 690

Schedule III................. 2,562 1,849 681 874 393 700

Schedule IV ................ 3,035 1,999 652 1,854 743 325

Schedule V ................. 654 609 . . . 235 86 56

No control.................. 65,532 46,018 9,657 32,427 13,877 7,672

Undetermined ............... 4,507 2,406 740 3,467 417 393

Percent distribution

All drug mentions ............. 100.0 100.0 100.0 100.0 100.0 100.0

Prescription status

Prescription ................. 82.7 83.8 82.7 85.1 80.7 74.5

Non-prescription1 ............. 9.8 9.3 9.6 7.9 11.9 14.4

Undetermined status ........... 7.5 6.8 7.7 7.0 7.4 11.1

Federal control status2

Schedule II ................. 2.2 1.4 1.3 2.1 2.4 7.0

Schedule III................. 2.3 1.9 3.2 1.1 1.9 6.3

Schedule IV ................ 3.1 2.5 2.4 4.4 3.1 3.4

Schedule V ................. 0.4 0.5 * 0.2 0.3 0.3

No control.................. 88.5 90.7 88.7 87.1 89.7 80.5

Undetermined ............... 3.5 3.0 4.2 5.1 2.6 2.5

Standard error of percent

All drug mentions ............. . . . . . . . . . . . . . . . . . .

Prescription status

Prescription ................. 0.4 0.6 0.9 0.8 0.6 0.5

Non-prescription1 ............. 0.2 0.4 0.7 0.4 0.4 0.3

Undetermined status ........... 0.2 0.3 0.5 0.7 0.3 0.3

See footnotes at end of table.
Page 16 [ Series 13, No. 163

Table 4. Number and percent distribution of drug mentions at ambulatory care visits with corresponding standard errors, by selected drug

characteristics according to setting type: United States, 2003–04—Con.

Primary Surgical Medical Hospital Hospital

Combined care specialty specialty outpatient emergency

Characteristic settings offices offices offices departments departments

Federal control status2 Standard error of percent

Schedule II ................. 0.1 0.1 0.2 0.2 0.3 0.2

Schedule III................. 0.1 0.2 0.4 0.2 0.2 0.2

Schedule IV ................ 0.1 0.1 0.4 0.3 0.3 0.1

Schedule V ................. 0.0 0.1 . . . 0.1 0.0 0.0

No control.................. 0.3 0.3 0.7 0.9 0.7 0.4

Undetermined ............... 0.2 0.2 0.4 0.7 0.1 0.1

* Figure does not meet standard of reliability or precision.

. . . Not applicable.

0.0 Quantity more than zero, but less than 0.05.

1

Nonprescription preparations include over-the-counter (OTC) products. Drug characteristics are defined in Appendix II.

2

See Appendix II for an explanation of federal control status.
Series 13, No. 163 [ Page 17

Table 5. Annual rate of broad therapeutic classes of drug mentions at ambulatory care visits, by setting type: United States, 2003–04

Primary Surgical Medical Hospital Hospital

Combined care specialty specialty outpatient emergency

Broad therapeutic class1 settings offices offices offices departments departments

Number of occurrences per 100 visits

Anesthetics and adjuncts ....................... 1.9 1.0 2.6 1.8 2.8 4.5

Antidotes ................................. 0.2 *0.0 *0.2 0.4 *0.2 0.4

Antimicrobial agents .......................... 16.0 18.8 7.8 8.9 18.0 27.2

Hematologic agents .......................... 3.9 3.5 1.1 7.8 4.7 2.9

Cardiovascular-renal drugs...................... 25.2 28.9 9.2 37.4 23.0 13.8

Central nervous system........................ 17.6 15.4 3.0 36.9 18.5 17.5

Contrast media and radiopharmaceuticals ............ 0.1 *0.1 *0.0 *0.3 *0.1 0.1

Gastrointestinal agents ........................ 9.1 9.9 2.9 11.4 9.6 11.0

Metabolics and nutrients ....................... 15.2 18.1 4.2 21.8 15.0 8.1

Hormones and hormonal mechanisms............... 15.2 18.8 6.1 17.4 15.5 8.7

Immunologics .............................. 6.3 8.5 *0.4 6.8 8.2 3.0

Skin/mucous membranes....................... 7.1 5.9 3.8 14.8 6.6 5.4

Neurologic drugs ............................ 5.5 4.2 1.8 11.6 6.7 5.9

Oncolytics ................................ 1.2 0.4 0.7 4.1 1.9 0.1

Ophthlamics ............................... 4.4 1.5 17.8 1.6 3.3 2.8

Otics ................................... 2.7 2.0 0.8 1.5 2.6 11.5

Relief of pain .............................. 25.7 22.8 14.0 21.6 27.2 64.7

Antiparasitics .............................. 0.8 0.9 0.2 0.6 1.2 0.8

Respiratory tract ............................ 20.7 24.1 6.2 22.1 21.6 24.3

Unclassified and miscellaneous ................... 3.7 3.4 2.3 5.1 3.1 5.3

Homeopathic products ........................ 0.6 0.7 0.4 0.8 0.4 0.1

Standard error of rate

Anesthetics and adjuncts ....................... 0.1 0.2 0.5 0.3 0.4 0.2

Antidotes ................................. 0.0 0.0 0.1 0.1 0.1 0.0

Antimicrobial agents .......................... 0.5 0.8 0.5 1.3 1.1 0.6

Hematologic agents .......................... 0.2 0.3 0.2 0.9 0.5 0.2

Cardiovascular-renal drugs...................... 1.2 1.9 1.2 3.7 1.9 0.8

Central nervous system........................ 0.6 0.9 0.5 2.3 1.5 0.6

Contrast media and radiopharmaceuticals ............ 0.0 0.0 0.0 0.1 0.0 0.0

Gastrointestinal agents ........................ 0.4 0.5 0.4 1.2 0.7 0.4

Metabolics and nutrients ....................... 0.8 1.2 0.5 2.4 1.3 0.5

Hormones and hormonal mechanisms............... 0.6 0.9 0.6 1.9 1.0 0.4

Immunologics .............................. 0.4 0.7 0.2 1.4 0.7 0.1

Skin and mucous membranes .................... 0.2 0.3 0.4 1.0 0.4 0.2

Neurologic drugs ............................ 0.2 0.3 0.4 0.8 0.5 0.2

Oncolytics ................................ 0.2 0.1 0.1 0.9 0.3 0.0

Ophthlamics ............................... 0.3 0.1 1.9 0.4 0.4 0.1

Otics ................................... 0.1 0.2 0.1 0.2 0.2 0.3

Relief of pain .............................. 0.7 1.2 1.4 1.8 1.6 1.0

Antiparasitics .............................. 0.1 0.1 0.0 0.1 0.1 0.0

Respiratory tract ............................ 0.8 1.1 0.6 3.2 1.3 0.5

Unclassified and miscellaneous ................... 0.3 0.4 0.3 0.6 0.3 0.4

Homeopathic products ........................ 0.1 0.1 0.1 0.2 0.1 0.0

* Figure does not meet standard of reliability or precision.

0.0 Quantity is greater than zero but less than 0.05.

1

Based on the standard drug classification used in the National Drug Code Directory, 1995 edition (NDC) (12). In the NDC, therapeutic classes are assigned to drugs using 21 broad categories (2-digit

level), and into specific categories (4-digit level) within each broad group. In NAMCS and NHAMCS, up to three therapeutic classes can be coded for each drug. Drugs are counted in each class in

which they occur.

NOTE: Figures are annual averages.
Page 18 [ Series 13, No. 163

Table 6. Annual rate of the top 10 broad therapeutic classes of drugs provided, prescribed, or continued at ambulatory care visits, with

corresponding standard errors, by setting type: United States, 2003–04

Setting type and Number of occurrences Standard error

broad therapeutic class1 per 100 visits of rate

Primary care offices

Cardiovascular-renal ....................... 28.9 1.9

Respiratory tract .......................... 24.1 1.1

Relief of pain ............................ 22.8 1.2

Hormones and hormonal mechanisms ............ 18.8 0.9

Antimicrobial agents ....................... 18.8 0.8

Metabolics and nutrients ..................... 18.1 1.2

Central nervous system ..................... 15.4 0.9

Gastrointestinal agents ...................... 9.9 0.5

Immunologics ........................... 8.5 0.7

Skin and mucous membranes ................. 5.9 0.3

Surgical specialty offices

Ophthalmics ............................ 17.8 1.9

Relief of pain ............................ 14.0 1.4

Cardiovascular-renal ....................... 9.2 1.2

Antimicrobial agents ....................... 7.8 0.5

Respiratory tract .......................... 6.2 0.6

Hormones and hormonal mechanisms ............ 6.1 0.6

Metabolics and nutrients ..................... 4.2 0.5

Skin and mucous membranes ................. 3.8 0.4

Central nervous system ..................... 3.0 0.5

Gastrointestinal agents ...................... 2.9 0.4

Medical specialty offices

Cardiovascular-renal ....................... 37.4 3.7

Central nervous system ..................... 36.9 2.3

Respiratory tract .......................... 22.1 3.2

Metabolics and nutrients ..................... 21.8 2.4

Relief of pain ............................ 21.6 1.8

Hormones and hormonal mechanisms ............ 17.4 1.9

Skin and mucous membranes ................. 14.8 1.0

Neurologics ............................. 11.6 0.8

Gastrointestinal agents ...................... 11.4 1.2

Antimicrobial agents ....................... 8.9 1.3

Hospital outpatient departments

Relief of pain ............................ 27.2 1.6

Cardiovascular-renal ....................... 23.0 1.9

Respiratory tract .......................... 21.6 1.3

Central nervous system ..................... 18.5 1.5

Antimicrobial agents ....................... 18.0 1.1

Hormones and hormonal mechanisms ............ 15.5 1.0

Metabolics and nutrients ..................... 15.0 1.3

Gastrointestinal agents ...................... 9.6 0.7

Immunologics ........................... 8.2 0.7

Neurologics ............................. 6.7 0.5

Hospital emergency departments

Relief of pain ............................ 64.7 1.0

Antimicrobial agents ....................... 27.2 0.6

Respiratory tract .......................... 24.3 0.5

Central nervous system ..................... 17.5 0.6

Cardiovascular-renal ....................... 13.8 0.8

Otics ................................. 11.5 0.3

Gastrointestinal agents ...................... 11.0 0.4

Hormones and hormonal mechanisms ............ 8.7 0.4

Metabolics and nutrients ..................... 8.1 0.5

Neurologics ............................. 5.9 0.2

1

Based on the standard drug classification used in the National Drug Code Directory, 1995 edition (NDC) (12). In the NDC, therapeutic classes are assigned to drugs using 21 broad categories (2-digit

level), and into specific categories (4-digit level) within each broad group. In NAMCS and NHAMCS, up to three therapeutic classes can be coded for each drug. Drugs are counted in each class in

which they occur.

NOTE: Figures are annual averages.
Series 13, No. 163 [ Page 19

Table 7. Annual number and rate of therapeutic classes of drugs provided, prescribed, or continued at ambulatory care visits, with percent

distribution by setting type and corresponding standard errors: United States, 2003–2004

Number of

Number of occurrences Primary Surgical Medical Hospital Hospital

occurrences per 1,000 care specialty specialty outpatient emergency

Therapeutic class1 in thousands2 drug mentions3 Total offices offices offices departments departments

Percent distribution

All occurrences...................... 2,240,800 1,150.4 100.0 49.7 7.4 22.5 8.4 12.0

Anesthetics and adjuncts................ 20,929 10.7 100.0 24.5 22.4 17.1 11.9 24.0

Anesthetics, local (injectable)............ 13,034 6.7 100.0 23.5 30.5 16.9 9.3 19.8

Anesthetics, general ................. *1,162 *0.6 100.0 * * * *47.6 *16.9

Adjuncts to anesthesia and analeptics ...... 3,488 1.8 100.0 * * *18.5 8.6 54.6

Medicinal gases .................... 1,643 0.8 100.0 * * * *8.6 40.4

Anesthetics, topical .................. 1,696 0.9 100.0 * * 42.4 10.3 15.3

Anesthetics, rectal .................. 522 0.3 100.0 * * * *12.5 13.0

Antidotes ......................... 1,820 0.9 100.0 * * 42.1 *10.6 23.3

Antidotes, specific................... 681 0.3 100.0 * * * *20.8 37.5

Antidotes, general................... 590 0.3 100.0 * * * * 27.6

Antitoxins or antivenins ............... 551 0.3 100.0 * * *35.4 * *

Antimicrobial agents................... 178,179 91.5 100.0 56.2 7.9 9.8 9.1 17.1

Penicillins ........................ 44,824 23.0 100.0 65.4 3.8 4.1 10.6 16.1

Cephalosporins .................... 30,104 15.5 100.0 52.1 7.9 4.1 7.9 28.0

Lincosamides and macrolides ........... 31,362 16.1 100.0 63.3 3.7 8.6 8.7 15.7

Tetracyclines ...................... 8,564 4.4 100.0 49.2 6.3 30.7 6.4 7.4

Aminoglycosides ................... 2,024 1.0 100.0 43.7 * * 10.6 18.1

Sulfonamides and trimethoprim .......... 9,566 4.9 100.0 54.8 5.0 13.2 9.6 17.5

Urinary tract antiseptics ............... 4,495 2.3 100.0 50.6 19.1 11.5 9.3 9.5

Miscellaneous antibacterial agents ........ 11,495 5.9 100.0 36.2 31.0 11.1 6.8 14.9

Antimycobacterial and anti-leprosy agents .... 347 0.2 100.0 * * * *18.3 *

Quinolones and derivatives ............. 19,787 10.2 100.0 54.3 12.1 5.7 6.8 21.1

Antifungals ....................... 4,304 2.2 100.0 62.4 * 20.7 12.0 2.6

Antiviral agents .................... 10,440 5.4 100.0 44.4 * *33.7 12.7 5.6

Hematologic agents ................... 43,571 22.4 100.0 43.4 4.5 35.0 9.7 7.4

Deficiency anemias .................. 17,971 9.2 100.0 51.2 2.0 33.9 10.0 2.8

Anticoagulants and thrombolytics ......... 25,022 12.8 100.0 38.2 6.4 35.5 9.6 10.2

Blood components and substitutes ........ *174 *0.1 100.0 * * * * *25.2

Hemostatics ...................... 358 0.2 100.0 * * * *8.6 31.7

Cardiovascular-renal drugs .............. 279,710 143.6 100.0 55.0 5.9 26.2 7.4 5.5

Cardiac glycosides .................. 7,907 4.1 100.0 45.6 5.8 36.4 6.8 5.4

Antiarrhythmic agents ................ 4,624 2.4 100.0 37.2 * 40.1 5.4 13.2

Antianginal agents .................. 12,596 6.5 100.0 35.7 3.4 33.7 5.3 21.8

Vascular disorders, cerebral and peripheral . . . 7,841 4.0 100.0 59.0 18.3 *16.6 5.5 0.6

Agents used to treat shock and hypotension . . 1,211 0.6 100.0 * * * *9.1 44.4

Antihypertensive agents ............... 69,625 35.7 100.0 61.5 5.6 24.1 6.0 2.7

Diuretics ........................ 50,605 26.0 100.0 54.1 4.4 27.0 8.4 6.0

Coronary vasodilators ................ 693 0.4 100.0 * * * *8.0 37.9

Relaxants and stimulants, urinary tract ...... 4,746 2.4 100.0 57.6 22.9 10.7 6.2 2.6

Calcium channel blockers .............. 37,156 19.1 100.0 57.8 4.7 25.5 7.6 4.4

Carbonic anhydrase inhibitors ........... 480 0.2 100.0 * * * *10.0 *

Beta blockers ..................... 46,478 23.9 100.0 53.5 4.9 29.1 8.4 4.1

Alpha agonists and alpha blockers ........ 24,320 12.5 100.0 45.4 10.4 30.3 7.0 6.9

ACE4 inhibitors .................... 49,721 25.5 100.0 61.8 4.5 22.5 8.1 3.1

Central nervous system ................ 195,747 100.5 100.0 41.9 2.7 36.9 8.5 10.0

Sedatives and hypnotics............... 34,523 17.7 100.0 37.1 3.6 19.6 9.2 30.5

Antianxiety agents .................. 32,505 16.7 100.0 41.1 4.3 34.6 6.5 13.5

Antipsychotics and antimanics ........... 17,382 8.9 100.0 20.2 * 59.7 12.3 7.2

Antidepressants .................... 89,218 45.8 100.0 47.2 2.7 38.8 8.6 2.7

Anorexiants and CNS5 stimulants ......... 13,195 6.8 100.0 54.5 * 37.2 6.8 1.2

CNS, miscellaneous ................. 3,180 1.6 100.0 34.3 * 52.0 7.1 2.1

Alzheimer-type dementia .............. 3,286 1.7 100.0 56.7 * 34.7 3.5 3.6

Antiemetics ....................... 2,629 1.3 100.0 * * 53.2 *8.8 23.9

Contrast media and radiopharmaceuticals ..... 1,195 0.6 100.0 * * 46.3 *8.4 12.7

Diagnostics, radiopaque and nonradioactive . . 870 0.4 100.0 * * 44.4 *10.6 17.2

Gastrointestinal agents ................. 101,157 51.9 100.0 52.1 5.1 22.0 8.5 12.2

Disorders, acid and peptic.............. 68,140 35.0 100.0 54.2 4.6 22.6 8.5 10.0

Antidiarrheals ..................... 5,585 2.9 100.0 53.3 * 19.9 7.5 16.3

Laxatives ........................ 13,494 6.9 100.0 47.6 *8.6 22.4 11.0 10.4

See footnotes at end of table.
Page 20 [ Series 13, No. 163

Table 7. Annual number and rate of therapeutic classes of drugs provided, prescribed, or continued at ambulatory care visits, with percent

distribution by setting type and corresponding standard errors: United States, 2003–2004—Con.

Number of

Number of occurrences Primary Surgical Medical Hospital Hospital

occurrences per 1,000 care specialty specialty outpatient emergency

Therapeutic class1 in thousands2 drug mentions3 Total offices offices offices departments departments

Percent distribution

Gastrointestinal agents—Con.

Miscellaneous gastrointestinals .......... 7,561 3.9 100.0 49.2 *5.1 24.4 4.3 17.0

Antispasmodics and anticholinergics ....... 3,341 1.7 100.0 44.6 8.0 * 7.4 23.8

Antacids......................... 3,662 1.9 100.0 40.2 * 15.8 9.6 32.4

Metabolics and nutrients ................ 169,099 86.8 100.0 57.1 4.4 25.2 8.0 5.3

Hyperlipidemia..................... 69,358 35.6 100.0 61.7 4.2 25.1 6.9 2.0

Vitamins and minerals ................ 49,789 25.6 100.0 59.4 5.2 22.2 10.1 3.0

Nutrition, enteral and parenteral .......... 3,561 1.8 100.0 49.3 * 27.0 9.5 13.6

Replenishers, regulators of electrolytes and

water balance .................... 28,914 14.8 100.0 45.6 4.8 23.6 7.2 18.8

Calcium metabolism ................. 13,929 7.2 100.0 61.6 3.1 28.2 6.0 1.1

Hematopoietic growth factors............ 2,968 1.5 100.0 * * 75.9 *9.6 *2.3

Hormones and hormonal mechanisms ....... 168,893 86.7 100.0 59.3 6.5 20.2 8.2 5.8

Adrenal corticosteroids................ 40,653 20.9 100.0 43.6 11.2 23.5 8.0 13.7

Androgens and anabolic steroids ......... 4,940 2.5 100.0 60.1 17.4 17.2 4.4 *0.9

Estrogens and progestins .............. 22,849 11.7 100.0 70.4 4.6 15.4 7.7 1.8

Anterior pituitary and hypothalmic function.... 324 0.2 100.0 * * * *25.0 *

Blood glucose regulators .............. 59,559 30.6 100.0 60.7 4.2 21.3 9.3 4.4

Thyroid and antithyroid................ 26,168 13.4 100.0 60.9 5.0 24.8 6.5 2.8

Antidiuretics ...................... 183 0.1 100.0 * * * * *

Relaxants and stimulants, uterine ......... *391 *0.2 100.0 * * * *18.4 *11.1

Contraceptives..................... 14,472 7.4 100.0 83.8 * 4.8 8.1 1.7

Growth hormone secretion disorders ....... 967 0.5 100.0 * 42.2 * *12.3 *

Immunologics ....................... 70,073 36.0 100.0 64.7 *1.0 18.9 10.6 4.9

Vaccines and antisera ................ 55,085 28.3 100.0 79.3 * *2.7 11.8 6.0

Immunomodulators .................. 3,753 1.9 100.0 * * 64.1 16.6 3.0

Allergenic extracts .................. 10,785 5.5 100.0 *9.2 *4.8 84.2 *1.7 *

Immune serums .................... 881 0.5 100.0 * * * *9.6 21.4

Skin and mucous membranes............. 79,135 40.6 100.0 39.6 8.7 36.6 7.5 7.6

Antiseptics and disinfectants ............ 4,966 2.5 100.0 22.8 *8.5 52.1 5.5 11.1

Dermatologics, miscellaneous ........... 23,400 12.0 100.0 47.0 3.4 36.9 7.6 5.0

Keratolytics ....................... 541 0.3 100.0 * * 58.7 *9.7 *

Topical steroids .................... 20,998 10.8 100.0 36.3 14.2 35.7 6.8 7.0

Burn and sunburn, sunscreen and suntan

products ........................ 420 0.2 100.0 * * 72.4 * *

Acne products ..................... 5,672 2.9 100.0 16.9 * 76.5 4.6 *

Topical anti-infectives................. 12,398 6.4 100.0 50.0 5.3 27.5 9.6 7.7

Anorectal products .................. *136 *0.1 100.0 * * * * *

Dermatitis and antipruritics ............. 1,563 0.8 100.0 * * 38.6 8.5 5.6

Topical analgesics .................. 9,910 5.1 100.0 38.1 18.7 16.9 8.4 18.0

Neurologic drugs..................... 60,978 31.3 100.0 36.9 5.3 37.1 9.8 10.9

Extrapyramidal movement disorders ....... 4,137 2.1 100.0 * * 59.0 9.5 4.9

Myasthenia gravis................... *86 *0.0 100.0 * * * * *

Skeletal muscle hyperactivity ............ 23,781 12.2 100.0 50.4 7.9 15.7 8.2 17.8

Anticonvulsants .................... 37,664 19.3 100.0 30.3 4.1 46.7 10.6 8.4

Oncolytics ......................... 13,119 6.7 100.0 15.4 9.3 61.1 12.9 1.2

Antineoplastics, miscellaneous ........... 4,658 2.4 100.0 * *5.0 70.1 11.4 1.3

Hormonal and biological response modulators . 3,822 2.0 100.0 * 22.5 47.1 8.9 1.6

Antimetabolites .................... 2,434 1.2 100.0 * * 56.8 13.8 *

Antibiotics, alkaloids, and enzymes ........ 432 0.2 100.0 * * 68.3 *21.6 *

DNA damaging drugs ................ 1,588 0.8 100.0 * * 69.0 *24.3 *

Ophthalmics........................ 49,201 25.3 100.0 16.3 65.1 6.3 6.1 6.3

Glaucoma........................ 12,516 6.4 100.0 7.9 80.8 4.6 5.8 0.9

Cycloplegics and mydriatics ............ 2,884 1.5 100.0 * 61.5 * 12.8 20.9

Ocular anti-infective and anti-inflammatory . . . 21,341 11.0 100.0 22.4 57.7 *6.7 6.2 7.0

Miscellaneous ophthalmics ............. 9,784 5.0 100.0 12.3 69.7 * 4.5 8.0

Decongestants and antiallergy agents ...... 2,039 1.0 100.0 40.4 32.1 * *3.4 2.8

Otics ............................ 30,101 15.5 100.0 34.9 4.9 9.7 7.7 42.8

Otic, topical (miscellaneous) ............ 4,923 2.5 100.0 57.8 15.5 * 10.2 14.3

Vertigo, motion sickness, and vomiting ...... 25,179 12.9 100.0 30.4 *2.8 11.2 7.3 48.4

Relief of pain ....................... 285,792 146.7 100.0 42.5 8.8 14.8 8.5 25.4

General analgesics .................. 5,813 3.0 100.0 48.5 11.6 23.9 5.8 10.3

Narcotic analgesics .................. 78,516 40.3 100.0 30.5 9.8 13.0 7.7 39.0

See footnotes at end of table.
Series 13, No. 163 [ Page 21

Table 7. Annual number and rate of therapeutic classes of drugs provided, prescribed, or continued at ambulatory care visits, with percent

distribution by setting type and corresponding standard errors: United States, 2003–2004—Con.

Number of

Number of occurrences Primary Surgical Medical Hospital Hospital

occurrences per 1,000 care specialty specialty outpatient emergency

Therapeutic class1 in thousands2 drug mentions3 Total offices offices offices departments departments

Percent distribution

Relief of pain—Con.

Nonnarcotic analgesics ............... 76,480 39.3 100.0 46.3 4.0 19.5 10.0 20.2

Antimigraine and other headaches ........ 6,741 3.5 100.0 70.0 * 16.1 7.2 4.5

Antiarthritics ...................... 66,733 34.3 100.0 50.3 11.7 24.0 7.5 6.5

Antigout ......................... 5,110 2.6 100.0 51.2 * 36.7 4.9 3.5

NSAID6 ......................... 111,974 57.5 100.0 46.7 11.0 11.0 8.6 22.7

Antipyretics ....................... 69,924 35.9 100.0 46.0 3.7 19.4 10.1 20.8

Antiparasitics ....................... 8,382 4.3 100.0 58.3 4.2 15.0 12.4 10.0

Antiprotozoals ..................... 6,213 3.2 100.0 60.6 3.3 11.8 12.5 11.8

Scabicides and pediculicides ............ *309 *0.2 100.0 * * * * *

Antimalarials ...................... 2,179 1.1 100.0 52.5 * 28.4 10.0 3.1

Respiratory tract ..................... 229,591 117.9 100.0 56.0 4.9 18.8 8.4 11.8

Antiasthmatics and bronchodilators ........ 79,790 41.0 100.0 51.8 3.1 26.1 7.9 11.1

Nasal decongestants ................. 17,284 8.9 100.0 66.7 9.0 5.5 11.0 7.9

Antitussives, expectorants. and mucolytics . . . 30,186 15.5 100.0 68.7 4.4 7.8 10.5 8.6

Antihistamines ..................... 79,432 40.8 100.0 53.2 4.2 17.0 7.7 17.8

Cold remedies ..................... 8,201 4.2 100.0 74.1 *3.7 * 8.2 7.1

Corticosteroid - inhalation and nasal ....... 30,950 15.9 100.0 58.8 10.0 20.5 8.8 1.9

Unclassified and miscellaneous............ 40,782 20.9 100.0 44.1 9.9 24.5 6.8 14.7

Unclassified ...................... 34,543 17.7 100.0 48.1 10.2 26.4 6.6 8.8

Pharmaceutical aids ................. 4,386 2.3 100.0 * *2.6 * 7.1 63.0

Surgical aids ...................... 1,832 0.9 100.0 * * * *4.7 68.5

Homeopathic products ................. 6,521 3.3 100.0 58.4 10.3 25.3 4.9 1.1

Standard Standard

error in error

Therapeutic class1 thousands of rate Standard error of percent

All drug mentions .................... 72,398 2.6 . . . 1.6 0.5 1.5 0.8 0.6

Anesthetics and adjuncts................ 1,482 0.8 . . . 3.8 3.6 2.9 1.9 1.8

Anesthetics, local (Injectable)............ 1,240 0.6 . . . 5.8 5.1 3.5 1.5 2.0

Anesthetics, general ................. 360 0.2 . . . . . . . . . . . . 15.1 5.4

Adjuncts to anesthesia and analeptics ...... 326 0.2 . . . . . . . . . 5.6 2.1 4.9

Medicinal gases .................... 267 0.1 . . . . . . . . . . . . 3.7 7.1

Anesthetics, topical .................. 345 0.2 . . . . . . . . . 12.0 2.8 3.6

Anesthetics, rectal .................. 118 0.1 . . . . . . . . . . . . 3.9 3.4

Antidotes ......................... 256 0.1 . . . . . . . . . 7.7 4.2 3.3

Antidotes, specific................... 118 0.1 . . . . . . . . . . . . 9.1 6.8

Antidotes, general................... 167 0.1 . . . . . . . . . . . . . . . 7.7

Antitoxins or antivenins ............... 161 0.1 . . . . . . . . . 12.2 . . . . . .

Antimicrobial agents................... 6,998 3.4 . . . 1.8 0.6 1.4 0.9 0.9

Penicillins ........................ 2,459 1.2 . . . 2.0 0.6 0.9 1.3 1.1

Cephalosporins .................... 1,633 0.8 . . . 2.4 1.2 0.7 1.0 1.7

Lincosamides and macrolides ........... 1,759 0.9 . . . 2.2 0.6 1.2 1.1 1.1

Tetracyclines ...................... 759 0.4 . . . 3.8 1.3 3.1 1.1 0.8

Aminoglycosides ................... 231 0.1 . . . 6.6 . . . . . . 2.4 2.3

Sulfonamides and trimethoprim .......... 808 0.4 . . . 4.4 0.9 3.8 1.2 1.9

Urinary tract antiseptics ............... 343 0.2 . . . 3.8 2.4 2.7 1.3 1.0

Miscellaneous antibacterial agents ........ 793 0.4 . . . 3.8 3.6 1.6 0.8 1.3

Antimycobacterial and anti-leprosy agents .... 103 0.1 . . . . . . . . . . . . 7.5 . . .

Quinolones and derivatives ............. 911 0.5 . . . 2.3 1.2 0.9 0.8 1.2

Antifungals ....................... 461 0.2 . . . 5.1 . . . 5.0 2.9 0.5

Antiviral agents .................... 1,902 1.0 . . . 8.4 . . . 11.3 3.6 1.2

Hematologic agents ................... 2,771 1.0 . . . 3.0 0.9 3.2 1.3 0.7

Deficiency anemias .................. 1,706 0.7 . . . 4.6 0.5 5.1 1.4 0.4

Anticoagulants and thrombolytics ......... 1,599 0.6 . . . 3.2 1.3 2.9 1.6 0.9

Blood components and substitutes ........ 107 0.1 . . . . . . . . . . . . . . . 16.0

Hemostatics ...................... 89 0.0 . . . . . . . . . . . . 3.5 8.3

Cardiovascular-renal drugs .............. 15,315 4.0 . . . 2.3 0.8 2.2 0.9 0.5

Cardiac glycosides .................. 611 0.3 . . . 4.1 1.7 3.9 1.3 0.7

Antiarrythmic agents ................. 433 0.2 . . . 4.8 . . . 4.3 1.5 1.6

Antianginal agents .................. 981 0.4 . . . 3.1 1.0 3.2 0.9 2.0

See footnotes at end of table.
Page 22 [ Series 13, No. 163

Table 7. Annual number and rate of therapeutic classes of drugs provided, prescribed, or continued at ambulatory care visits, with percent

distribution by setting type and corresponding standard errors: United States, 2003–2004—Con.

Number of

Number of occurrences Primary Surgical Medical Hospital Hospital

occurrences per 1,000 care specialty specialty outpatient emergency

Therapeutic class1 in thousands2 drug mentions3 Total offices offices offices departments departments

Standard Standard

error in error

thousands of rate Standard error of percent

Cardiovascular-renal drugs—Con.

Vascular disorders, cerebral and peripheral . . . 801 0.4 . . . 4.9 2.6 5.7 1.0 0.2

Agents used to treat shock and hypotension . . 230 0.1 . . . . . . . . . . . . 2.7 8.6

Antihypertensive agents ............... 4,320 1.4 . . . 2.9 0.9 2.6 0.8 0.3

Diuretics ........................ 3,025 1.0 . . . 2.9 0.8 2.9 1.0 0.6

Coronary vasodilators ................ 102 0.1 . . . . . . . . . . . . 3.0 6.1

Relaxants and stimulants, urinary tract ...... 455 0.2 . . . 4.2 2.7 2.5 1.2 0.5

Calcium channel blockers .............. 2,381 0.8 . . . 2.6 1.0 2.4 1.0 0.5

Carbonic anhydrase inhibitors ........... 100 0.1 . . . . . . . . . . . . 4.2 . . .

Beta blockers ..................... 2,762 0.9 . . . 2.5 0.8 2.4 1.2 0.4

Alpha agonists and alpha blockers ........ 1,428 0.5 . . . 2.7 1.2 2.5 1.0 0.6

ACE4 inhibitors .................... 3,007 0.9 . . . 2.5 0.8 2.2 1.0 0.4

Central nervous system ................ 8,530 2.7 . . . 1.9 0.4 2.0 1.0 0.6

Sedatives and hypnotics............... 1,852 0.7 . . . 2.3 0.9 1.8 1.4 1.7

Antianxiety agents .................. 1,714 0.6 . . . 2.6 0.8 2.7 1.0 0.8

Antipsychotics and antimanics ........... 1,460 0.7 . . . 2.8 . . . 3.5 1.8 0.8

Antidepressants .................... 4,106 1.4 . . . 2.1 0.4 2.2 1.1 0.3

Anorexiants and CNS5 stimulants ......... 1,418 0.7 . . . 4.9 . . . 4.6 1.3 0.3

CNS, miscellaneous ................. 383 0.2 . . . 5.7 . . . 5.9 1.4 0.5

Alzheimer-type dementia .............. 545 0.3 . . . 7.4 . . . 6.4 1.0 0.9

Antiemetics ....................... 561 0.3 . . . . . . . . . 10.1 3.0 5.8

Contrast media and radiopharmaceuticals ..... 219 0.1 . . . . . . . . . 10.3 3.5 3.4

Diagnostics, radiopaque and nonradioactive . . 147 0.1 . . . . . . . . . 10.6 4.6 4.6

Gastrointestinal agents ................. 5,429 1.5 . . . 2.2 0.7 2.3 1.0 0.7

Disorders, acid and peptic.............. 3,759 1.0 . . . 2.3 0.6 2.4 1.0 0.7

Antidiarrheals ..................... 547 0.2 . . . 4.0 . . . 3.3 1.4 1.9

Laxatives ........................ 1,292 0.6 . . . 4.9 3.0 5.1 1.7 1.0

Miscellaneous gastrointestinals .......... 705 0.3 . . . 3.5 1.7 3.3 0.7 1.8

Antispasmodics and anticholinergics ....... 306 0.1 . . . 4.8 2.0 . . . 1.4 2.4

Antacids......................... 344 0.2 . . . 4.8 . . . 3.4 1.7 3.0

Metabolics and nutrients ................ 9,842 2.7 . . . 2.5 0.6 2.4 1.0 0.4

Hyperlipidemia..................... 4,440 1.3 . . . 2.6 0.7 2.3 1.0 0.3

Vitamins and minerals ................ 3,383 1.2 . . . 2.8 0.8 2.5 1.3 0.4

Nutrition, enteral and parenteral .......... 411 0.2 . . . 5.7 . . . 5.7 1.9 1.8

Replenishers, regulators of electrolytes and

water balance .................... 1,931 0.7 . . . 3.1 0.9 3.4 1.1 1.5

Calcium metabolism ................. 1,281 0.5 . . . 4.6 0.7 4.5 1.3 0.2

Hematopoietic growth factors............ 814 0.4 . . . . . . . . . 7.5 3.4 0.8

Hormones and hormonal mechanisms ....... 8,421 2.4 . . . 2.2 0.7 2.2 0.9 0.4

Adrenal corticosteroids................ 2,122 0.9 . . . 2.6 1.4 3.1 0.8 1.0

Androgens and anabolic steroids ......... 946 0.5 . . . 7.7 3.8 5.0 1.1 0.3

Estrogens and progestins .............. 1,730 0.7 . . . 2.7 1.0 2.3 1.2 0.3

Anterior pituitary and hypothalmic function.... 97 0.0 . . . . . . . . . . . . 8.4 . . .

Blood glucose regulators .............. 4,134 1.6 . . . 3.1 0.8 3.1 1.2 0.4

Thyroid and antithyroid................ 1,861 0.7 . . . 3.4 1.1 3.6 1.0 0.4

Antidiuretics ...................... 47 0.0 . . . . . . . . . . . . . . . . . .

Relaxants and stimulants, uterine ......... 182 0.1 . . . . . . . . . . . . 11.1 6.0

Contraceptives..................... 1,271 0.6 . . . 2.0 . . . 1.2 1.3 0.3

Growth hormone secretion disorders ....... 164 0.1 . . . . . . 7.7 . . . 5.2 . . .

Immunologics ....................... 4,622 2.3 . . . 3.7 0.4 3.7 1.4 0.4

Vaccines and antisera ................ 3,608 1.9 . . . 2.1 . . . 0.9 1.7 0.5

Immunomodulators .................. 751 0.4 . . . . . . . . . 8.2 4.3 0.8

Allergenic extracts .................. 2,971 1.5 . . . 5.1 2.9 6.4 0.6 . . .

Immune serums .................... 202 0.1 . . . . . . . . . . . . 3.2 5.6

Skin and mucous membrane ............. 3,265 1.5 . . . 1.9 1.1 2.0 0.7 0.5

Antiseptics and disinfectants ............ 494 0.2 . . . 3.6 3.0 4.7 1.6 1.5

Dermatologics, miscellaneous ........... 1,287 0.6 . . . 2.4 0.9 2.3 0.8 0.4

Keratolytics ....................... 91 0.0 . . . . . . . . . 8.5 3.2 . . .

Topical steroids .................... 1,306 0.6 . . . 3.0 2.7 2.9 0.9 0.6

See footnotes at end of table.
Series 13, No. 163 [ Page 23

Table 7. Annual number and rate of therapeutic classes of drugs provided, prescribed, or continued at ambulatory care visits, with percent

distribution by setting type and corresponding standard errors: United States, 2003–2004—Con.

Number of

Number of occurrences Primary Surgical Medical Hospital Hospital

occurrences per 1,000 care specialty specialty outpatient emergency

Therapeutic class1 in thousands2 drug mentions3 Total offices offices offices departments departments

Standard Standard

error in error

thousands of rate Standard error of percent

Skin and mucous membrane—Con.

Burn and sunburn, sunscreen and suntan

products ........................ 108 0.1 . . . . . . . . . 9.6 . . . . . .

Acne products ..................... 540 0.3 . . . 4.0 . . . 4.2 0.9 . . .

Topical anti-infectives................. 740 0.3 . . . 3.1 0.9 2.7 1.0 0.8

Anorectal products .................. 49 0.0 . . . . . . . . . . . . . . . . . .

Dermatitis and antipruritics ............. 215 0.1 . . . . . . . . . 5.4 2.2 1.4

Topical analgesics .................. 1,059 0.5 . . . 6.4 3.4 3.7 1.5 2.1

Neurologic drugs..................... 2,793 1.0 . . . 2.0 1.1 2.2 1.0 0.7

Extrapyramidal movement disorders ....... 452 0.2 . . . . . . . . . 4.9 1.7 0.9

Myasthenia gravis................... 32 0.0 . . . . . . . . . . . . . . . . . .

Skeletal muscle hyperactivity ............ 1,245 0.6 . . . 2.8 2.2 2.3 1.2 1.2

Anticonvulsants .................... 2,093 0.8 . . . 2.1 0.7 2.5 1.2 0.6

Oncolytics ......................... 2,079 1.0 . . . 3.7 1.7 6.4 2.7 0.3

Antineoplastics, miscellaneous ........... 1,078 0.5 . . . . . . 1.6 7.5 3.1 0.4

Hormonal and biological response modulators . 563 0.3 . . . . . . 4.0 7.5 1.9 0.5

Antimetabolites .................... 484 0.2 . . . . . . . . . 9.6 3.6 . . .

Antibiotics, alkaloids, and enzymes ........ 103 0.1 . . . . . . . . . 8.8 7.0 . . .

DNA damaging drugs ................ 396 0.2 . . . . . . . . . 8.9 7.5 . . .

Ophthalmics........................ 3,828 1.9 . . . 1.8 3.3 1.6 1.0 0.6

Glaucoma........................ 1,387 0.7 . . . 2.1 3.0 1.3 1.3 0.2

Cycloplegics and mydriatics ............ 434 0.2 . . . . . . 6.0 . . . 3.8 3.3

Ocular anti-infective and anti-inflammatory . . . 1,739 0.9 . . . 2.7 4.0 2.3 1.0 0.7

Miscellaneous ophthalmics ............. 1,476 0.7 . . . 2.7 4.9 . . . 1.2 1.4

Decongestants and antiallergy agents ...... 354 0.2 . . . 8.4 8.7 . . . 1.2 0.8

Otics ............................ 1,326 0.6 . . . 2.3 0.8 1.7 0.9 1.9

Otic, topical (miscellaneous) ............ 419 0.2 . . . 3.4 2.0 . . . 1.6 1.4

Vertigo, motion sickness, and vomiting ...... 1,141 0.5 . . . 2.4 0.8 2.0 0.9 2.1

Relief of pain ....................... 10,853 2.9 . . . 1.7 0.9 1.5 0.8 1.1

General analgesics .................. 672 0.3 . . . 4.8 2.9 4.8 1.1 1.4

Narcotic analgesics .................. 3,214 1.4 . . . 1.8 1.2 1.9 1.0 1.5

Non-narcotic analgesics ............... 4,118 1.3 . . . 2.4 0.6 1.7 1.1 1.3

Antimigraine and other headaches ........ 518 0.3 . . . 3.1 . . . 2.3 1.4 0.5

Antiarthritics ...................... 4,078 1.3 . . . 2.8 1.3 2.3 1.0 0.6

Antigout ......................... 547 0.2 . . . 5.2 . . . 5.3 1.1 0.6

NSAID6 ......................... 4,519 1.6 . . . 2.0 1.1 1.5 0.8 1.2

Antipyretics ....................... 3,948 1.3 . . . 2.4 0.6 1.7 1.1 1.3

Antiparasitics ....................... 618 0.3 . . . 3.4 0.8 2.7 1.6 0.9

Antiprotozoals ..................... 551 0.3 . . . 3.8 0.8 2.5 1.7 1.2

Scabicides and pediculicides ............ 113 0.1 . . . . . . . . . . . . . . . . . .

Antimalarials ...................... 267 0.1 . . . 6.5 . . . 6.6 2.7 0.7

Respiratory tract ..................... 11,629 4.1 . . . 2.3 0.5 2.6 0.9 0.7

Antiasthmatics and bronchodilators ........ 5,085 2.1 . . . 3.0 0.5 3.6 1.0 0.8

Nasal decongestants ................. 1,511 0.7 . . . 3.1 1.7 1.5 1.5 0.9

Antitussives, expectorants. and mucolytics . . . 2,140 1.0 . . . 2.5 1.0 1.3 1.6 0.8

Antihistamines ..................... 4,110 1.5 . . . 2.4 0.5 2.4 0.8 1.0

Cold remedies ..................... 1,185 0.6 . . . 4.3 1.2 . . . 1.9 1.2

Corticosteroid - inhalation and nasal ....... 2,160 0.9 . . . 3.2 1.3 3.6 1.2 0.2

Unclassified and miscellaneous............ 2,795 1.2 . . . 2.7 1.3 2.4 0.8 1.2

Unclassified ...................... 2,662 1.2 . . . 2.9 1.4 2.7 0.8 1.0

Pharmaceutical aids ................. 448 0.2 . . . . . . 1.3 . . . 1.4 5.5

Surgical aids ...................... 353 0.2 . . . . . . . . . . . . 1.5 11.9

Homeopathic products ................. 757 0.3 . . . 5.3 2.3 4.7 1.3 0.3

* Figure does not meet standard of reliability or precision. ...Category not applicable. 0.0 Quantity more than zero, but less than 0.05.

1

Based on the standard drug classification used in the National Drug Code Directory, 1995 edition (12). In the NDC, therapeutic classes are assigned to drugs using 21 broad categories (2-digit level),

and into specific categories (4-digit level) within each broad group. In NAMCS and NHAMCS, up to three therapeutic classes can be coded for each drug. Drugs are counted in each class in which

they occur.

2

Total of all therapeutic classes will exceed total number of drug mentions because up to three classes may be coded for each drug.

3

Based on an estimated annual average of 1,947,870,000 drug mentions at ambulatory care visits in 2003–04.

4

ACE is angiotensin converting enzyme.

5

CNS is central nervous system.

6

NSAID is nonsteroidal anti-inflammatory drug.

NOTES: Numbers may not add to totals because of rounding and because subcategories with fewer than 30 records were omitted. Figures are annual averages.
Page 24 [ Series 13, No. 163

Table 8. Annual number and percent distribution of the 50 most frequently occurring generic equivalents at ambulatory care visits, with

therapeutic class and corresponding standard errors: United States, 2003–04

Number of Standard Standard

mentions error in Percent error of

Generic substance in thousands thousands distribution percent Specific therapeutic class1

All drug mentions .................. 1,947,870 72,398 100.0 . . . . . .

Ibuprofen ....................... 41,039 2,152 2.1 0.1 NSAID2

Aspirin......................... 39,597 3,268 2.0 0.1 Non-narcotic analgesics; antiarthritics; antipyretics

Atorvastatin calcium ................ 32,643 2,422 1.7 0.1 Hyperlipidemia

Acetaminophen ................... 31,694 1,878 1.6 0.1 Non-narcotic analgesics; antipyretics

Albuterol ....................... 30,039 1,858 1.5 0.1 Antiasthmatics and bronchodilators

Acetaminophen with hydrocodone........ 28,984 1,515 1.5 0.1 Narcotic analgesics

Amoxicillin ...................... 25,964 1,741 1.3 0.1 Penicillins

Levothyroxine .................... 24,019 1,705 1.2 0.1 Thyroid and antithyroid

Furosemide...................... 22,289 1,638 1.1 0.1 Diuretics

Metoprolol ...................... 22,063 1,440 1.1 0.1 Beta blockers

Lisinopril ....................... 19,992 1,632 1.0 0.1 ACE3 inhibitors

Azithromycin ..................... 19,427 1,283 1.0 0.1 Lincosamides and macrolides

Hydrochlorothiazide................. 18,604 1,262 1.0 0.0 Diuretics

Atenolol ........................ 18,106 1,429 0.9 0.1 Beta blockers

Prednisone ...................... 16,616 1,638 0.9 0.1 Adrenal corticosteroids

Metformin....................... 15,685 1,199 0.8 0.0 Blood glucose regulators

Fluticasone propionate............... 15,568 1,108 0.8 0.0 Topical steroids; corticosteroid - inhalation and nasal

Amlodipine ...................... 15,060 1,072 0.8 0.0 Calcium channel blockers

Naproxen ....................... 14,975 899 0.8 0.0 NSAID2

Simvastatin...................... 14,891 1,246 0.8 0.0 Hyperlipidemia

Promethazine .................... 14,378 821 0.7 0.0 Antihistamines; vertigo, motion sickness, and vomiting;

sedatives and hypnotics

Amoxicillin with clavulanate ............ 14,136 1,040 0.7 0.1 Penicillins

Warfarin sodium ................... 13,858 1,114 0.7 0.0 Anticoagulants and thrombolytics

Cetirizine ....................... 13,778 1,390 0.7 0.1 Antihistamines

Celecoxib ....................... 13,236 944 0.7 0.0 Antiarthritics; NSAID2

Lansoprazole..................... 12,905 974 0.7 0.0 Acid and peptic disorders

Cephalexin ...................... 12,755 695 0.7 0.0 Cephalosporins

Fluticasone with salmeterol ............ 12,682 1,162 0.7 0.1 Antiasthmatics and bronchodilators

Rofecoxib....................... 12,515 941 0.6 0.0 NSAID2

Sertraline ....................... 12,416 816 0.6 0.0 Antidepressants

Alprazolam ...................... 12,307 877 0.6 0.0 Antianxiety agents

Fexofenadine .................... 12,113 1,044 0.6 0.0 Antihistamines

Montelukast sodium ................ 11,952 1,222 0.6 0.1 Antiasthmatics and bronchodilators

Triamcinolone .................... 11,664 874 0.6 0.0 Topical steroids; corticosteroid - nasal and inhalation;

antiasthmatics and bronchodilators

Paroxetine hydrochloride ............. 11,394 758 0.6 0.0 Antidepressants

Escitalopram oxalate ................ 11,151 879 0.6 0.0 Antidepressants

Influenza virus vaccine............... 10,478 1,787 0.5 0.1 Vaccines and antisera

Esomeprazole magnesium ............ 10,280 978 0.5 0.0 Acid and peptic disorders

Fluoxetine hydrochloride.............. 10,064 676 0.5 0.0 Antidepressants

Lidocaine ....................... 9,969 1,114 0.5 0.1 Anesthetics, topical; anesthetics, local (injectable);

antiarrhythmic agents

Pantoprazole sodium................ 9,932 931 0.5 0.0 Acid and peptic disorders

Potassium replacement solutions ........ 9,924 805 0.5 0.0 Replenishers and regulators of electrolytes and water

balance

Methylprednisolone ................. 9,783 737 0.5 0.0 Adrenal corticosteroids

Insulin ......................... 9,453 853 0.5 0.0 Blood glucose regulators

Acetaminophen with oxycodone ......... 9,401 749 0.5 0.0 Narcotic analgesics

Ketorolac tromethamine .............. 9,203 519 0.5 0.0 NSAID2

Bupropion....................... 9,203 642 0.5 0.0 Antidepressants; pharmaceutical aids

Estrogens....................... 9,106 825 0.5 0.0 Estrogens and progestins

Diphenhydramine .................. 8,988 611 0.5 0.0 Antihistamines

Sulfamethoxazole with trimethoprim....... 8,856 765 0.5 0.0 Sulfonamides and trimethoprim

All other ....................... 1,142,735 41,636 58.7 0.0 . . .

...Category not applicable.

0.0 Quantity more than zero, but less than 0.05.

1

Based on the standard drug classification used in the National Drug Code Directory, 1995 edition (NDC) (12). In the NDC, therapeutic classes are assigned to drugs using 21 broad categories (2-digit

level), and into specific categories (4-digit level) within each broad group. In NAMCS and NHAMCS, up to three therapeutic classes can be coded for each drug. Drugs are counted in each class in

which they occur.

2

NSAID is nonsteroidal anti-inflammatory drug.

3

ACE is angiotensin converting enzyme.

NOTES: Numbers may not add to totals due to rounding. Figures are annual averages.
Series 13, No. 163 [ Page 25

Table 9. Annual number and percent distribution of the generic equivalents most frequently provided, prescribed, or continued at

ambulatory care visits, by setting type, with corresponding standard errors: United States, 2003–04

Number of Standard Standard

drug mentions error in Percent error of

Selected characteristic in thousands thousands distribution percent Specific therapeutic class1

Primary care offices

All drug mentions .................. 975,895 50,268 100.0 . . . . . .

Atorvastatin calcium ................ 20,630 1,912 2.1 0.1 Hyperlipidemia

Aspirin......................... 19,084 2,503 2.0 0.2 Non-narcotic analgesics; antiarthritics; antipyretics

Amoxicillin ...................... 18,026 1,569 1.8 0.1 Penicillins

Ibuprofen ....................... 16,940 1,633 1.7 0.1 NSAID2

Albuterol ....................... 15,866 1,297 1.6 0.1 Antiasthmatics and bronchodilators

Levothyroxine .................... 14,847 1,226 1.5 0.1 Thyroid and antithyroid

Acetaminophen ................... 13,426 1,614 1.4 0.2 Non-narcotic analgesics; antipyretics

Azithromycin ..................... 12,783 1,216 1.3 0.1 Lincosamides and macrolides

Lisinopril ....................... 12,737 1,398 1.3 0.1 ACE3 inhibitors

Hydrochlorothiazide................. 12,077 1,082 1.2 0.1 Diuretics

All other........................ 819,479 41,805 84.1 0.4 . . .

Surgical specialty offices

All drug mentions .................. 147,946 10,949 100.0 . . . . . .

Prednisolone ..................... 4,255 703 2.9 0.4 Adrenal corticosteroids; ocular anti-infective and

anti-inflammatory

Acetaminophen with hydrocodone........ 3,835 652 2.6 0.4 Narcotic analgesics

Latanoprost...................... 2,663 391 1.8 0.2 Glaucoma

Celecoxib ....................... 2,563 411 1.7 0.2 Antiarthritics; NSAID2

Rofecoxib....................... 2,214 344 1.5 0.2 NSAID2

Dexamethasone with tobramycin ........ 2,022 456 1.4 0.3 Ocular anti-infective and anti-inflammatory

Aspirin......................... 1,924 361 1.3 0.2 Non-narcotic analgesics; antiarthritics; antipyretics

Naproxen ....................... 1,918 360 1.3 0.2 NSAID2

Lidocaine ....................... 1,899 291 1.3 0.2 Anesthetics, topical; anesthetics, local (injectable);

antiarrhythmic agents

Brimonidine...................... 1,813 329 1.2 0.2 Unclassified

All other........................ 122,841 9,169 83.0 0.8 . . .

Medical specialty offices

All drug mentions .................. 445,540 36,163 100.0 . . . . . .

Aspirin......................... 12,028 1,275 2.7 0.2 Non-narcotic analgesics; antiarthritics; antipyretics

Furosemide...................... 7,743 1,065 1.7 0.2 Diuretics

Atorvastatin calcium ................ 7,593 988 1.7 0.1 Hyperlipidemia

Metoprolol ...................... 7,297 814 1.6 0.1 Beta blockers

Levothyroxine .................... 5,757 1,035 1.3 0.2 Thyroid and antithyroid

Prednisone ...................... 5,528 1,336 1.2 0.3 Adrenal corticosteroids

Albuterol ....................... 5,385 1,193 1.2 0.2 Antiasthmatics and bronchodilators

Warfarin sodium ................... 5,262 683 1.2 0.1 Anticoagulants and thrombolytics

Sertraline ....................... 4,692 477 1.1 0.1 Antidepressants

Atenolol ........................ 4,680 648 1.1 0.1 Beta blockers

All others ....................... 379,575 30,240 85.2 0.7 . . .

Hospital outpatient departments

All drug mentions .................. 164,578 15,408 100.0 . . . . . .

Ibuprofen ....................... 4,542 487 2.8 0.2 NSAID2

Acetaminophen ................... 4,011 452 2.4 0.2 Non-narcotic analgesics; antipyretics

Albuterol ....................... 3,216 362 2.0 0.1 Antiasthmatics and bronchodilators

Aspirin......................... 3,147 536 1.9 0.2 Non-narcotic analgesics; antiarthritics; antipyretics

Amoxicillin ...................... 2,861 390 1.7 0.2 Penicillins

Atorvastatin calcium ................ 2,347 371 1.4 0.1 Hyperlipidemia

Hydrochlorothiazide................. 2,109 253 1.3 0.1 Diuretics

Acetaminophen with hydrocodone........ 1,967 286 1.2 0.1 Narcotic analgesics

Metoprolol ...................... 1,938 276 1.2 0.1 Beta blockers

Azithromycin ..................... 1,730 209 1.1 0.1 Lincosamides and macrolides

All other........................ 136,710 12,960 83.0 0.6 . . .

See footnotes at end of table.
Page 26 [ Series 13, No. 163

Table 9. Annual number and percent distribution of the generic equivalents most frequently provided, prescribed, or continued at

ambulatory care visits, by setting type, with corresponding standard errors: United States, 2003–04—Con.

Number of Standard Standard

drug mentions error in Percent error of

Selected characteristic in thousands thousands distribution percent Specific therapeutic class1

Hospital emergency departments

All drug mentions .................. 213,909 9,218 100.0 . . . . . .

Ibuprofen ....................... 15,199 786 7.1 0.2 NSAID2

Acetaminophen ................... 11,340 592 5.3 0.2 Non-narcotic analgesics; antipyretics

Acetaminophen with hydrocodone........ 11,050 601 5.2 0.2 Narcotic analgesics

Antihistamines; vertigo, motion sickness and vomiting;

Promethazine .................... 8,547 443 4.0 0.2 sedatives and hypnotics

Ketorolac tromethamine .............. 6,293 292 2.9 0.1 NSAID2

Albuterol ....................... 5,030 253 2.4 0.1 Antiasthmatics and bronchodilators

Morphine ....................... 4,662 252 2.2 0.1 Narcotic analgesics

Amoxicillin ...................... 3,626 246 1.7 0.1 Penicillins

Azithromycin ..................... 3,473 197 1.6 0.1 Lincosamides and macrolides

Aspirin......................... 3,415 239 1.6 0.1 Non-narcotic analgesics; antiarthritics; antipyretics

All other........................ 141,275 6,441 66.0 0.5 . . .

...Category not applicable.

1 Based on the standard drug classification used in the National Drug Code Directory, 1995 edition (NDC) (12). In the NDC, therapeutic classes are assigned to drugs using 21 broad categories (2-digit

level), and into specific categories (4-digit level) within each broad group. In NAMCS and NHAMCS, up to three therapeutic classes can be coded for each drug. Drugs are counted in each class in

which they occur.

2

NSAID is nonsteroidal anti-inflammatory drug.

3

ACE is angiotensin converting enzyme.

NOTES: Numbers may not add to totals due to rounding. Figures are annual averages.
Series 13, No. 163 [ Page 27

Table 10. Annual population rates for the top 20 specific therapeutic classes of drug mentions at ambulatory care visits, by patient age and

sex: United States, 2003–04

Patient age in years Sex

75

Specific therapeutic class1 Total Under 15 15–24 25–44 45–64 65–74 or more Female Male

Number of occurrences per 1,000 persons2

NSAID3 .......................... 390.3 242.1 259.4 349.3 482.6 696.0 742.2 440.3 337.9

Antidepressants ..................... 310.9 65.4 175.4 310.8 492.4 492.7 587.3 410.4 206.8

Antiasthmatics and bronchodilators ......... 278.0 335.8 126.2 155.8 336.4 510.1 548.2 311.8 242.6

Antihistamines ...................... 276.9 301.4 199.5 243.9 302.7 390.5 307.1 339.2 211.6

Narcotic analgesics ................... 273.5 36.9 185.8 332.7 389.1 391.1 451.5 317.6 227.4

Non-narcotic analgesics ................ 266.6 223.9 90.5 114.7 294.8 690.5 1,034.0 280.1 252.3

Antipyretics ........................ 243.7 222.6 84.0 92.8 255.8 644.6 980.6 248.6 238.6

Antihypertensive agents ................ 242.5 *2.6 *11.6 65.4 406.2 848.0 1,230.0 273.4 210.3

Hyperlipidemia ...................... 241.7 *3.7 *4.8 50.0 429.3 983.6 1,058.0 238.4 245.1

Acid and peptic disorders ............... 237.4 41.5 53.3 146.5 359.3 676.1 876.1 271.1 202.3

Antiarthritics........................ 232.6 *6.4 26.6 95.4 354.8 829.8 1,094.0 243.7 221.0

Blood glucose regulators ................ 207.5 *11.2 20.2 69.1 374.4 760.3 775.0 216.1 198.5

Vaccines and antisera ................. 192.0 601.3 59.1 55.0 73.4 179.6 205.4 188.3 195.9

Diuretics .......................... 176.4 4.8 *5.3 40.4 243.8 628.2 1,134.0 207.6 143.6

Vitamins and minerals ................. 173.5 54.3 95.4 117.0 199.6 424.7 704.6 236.4 107.6

ACE4 inhibitors ...................... 173.2 *4.1 *4.0 47.7 273.5 636.1 912.8 175.6 170.8

Beta blockers ....................... 161.9 4.5 11.4 42.1 234.0 625.7 901.2 180.6 142.4

Penicillins ......................... 156.3 382.5 119.0 99.3 83.5 81.8 85.0 160.9 151.4

Adrenal corticosteroids ................. 141.7 125.4 65.2 95.2 173.3 294.7 320.5 150.8 132.1

Anticonvulsants...................... 131.3 38.2 69.2 138.1 193.8 214.0 239.2 154.8 106.7

Standard error of rate

NSAID3 .......................... 15.7 23.7 14.7 16.0 25.8 52.3 57.8 18.6 15.3

Antidepressants ..................... 14.3 8.2 13.2 15.9 26.7 51.3 53.5 20.0 11.7

Antiasthmatics and bronchodilators ......... 17.7 29.5 11.5 15.0 28.1 53.7 60.4 21.1 17.4

Antihistamines ...................... 14.3 26.9 14.8 14.7 18.3 37.5 34.7 18.6 12.0

Narcotic analgesics ................... 11.2 3.0 11.8 15.8 18.5 35.5 32.3 13.7 10.1

Non-narcotic analgesics ................ 14.4 23.6 5.8 6.7 22.3 55.1 84.6 14.7 15.9

Antipyretics ........................ 13.8 23.8 5.6 6.4 21.1 51.6 80.3 13.8 15.4

Antihypertensive agents ................ 15.1 1.0 4.1 6.1 30.9 64.3 102.9 18.3 15.0

Hyperlipidemia ...................... 15.5 1.4 2.0 5.4 29.4 70.5 96.7 16.6 17.4

Acid and peptic disorders ............... 13.1 6.9 5.5 8.7 23.3 54.8 74.7 15.7 12.9

Antiarthritics........................ 14.2 2.1 3.8 6.7 27.6 60.1 89.8 14.0 16.4

Blood glucose regulators ................ 14.4 4.5 4.9 7.9 30.1 80.7 68.2 17.5 15.5

Vaccines and antisera ................. 12.6 51.2 6.3 6.6 9.0 35.8 39.1 14.4 14.2

Diuretics .......................... 10.5 1.3 1.7 4.0 17.2 48.3 89.1 14.0 9.9

Vitamins and minerals ................. 11.8 9.2 18.1 13.3 19.5 47.3 75.3 17.7 8.4

ACE4 inhibitors ...................... 10.5 1.3 1.2 5.4 19.5 46.8 70.4 11.6 11.2

Beta blockers ....................... 9.6 1.1 2.8 4.1 17.5 46.4 70.1 10.7 10.4

Penicillins ......................... 8.6 27.7 10.2 7.3 7.3 14.6 13.5 9.2 9.4

Adrenal corticosteroids ................. 7.4 10.5 6.3 8.2 13.3 29.4 32.6 8.8 8.1

Anticonvulsants...................... 7.3 6.4 6.7 9.6 13.5 26.9 27.2 9.5 6.9

* Figure does not meet standard of reliability or precision.

1

Based on the standard drug classification used in the National Drug Code Directory, 1995 edition (NDC) (12). In the NDC, therapeutic classes are assigned to drugs using 21 broad categories (2-digit

level), and into specific categories (4-digit level) within each broad group. In NAMCS and NHAMCS, up to three therapeutic classes can be coded for each drug. Drugs are counted in each class in

which they occur.

2

Estimates of the civilian noninstitutionalized population used in computing visit rates by age and sex are from special tabulations developed by the Population Division, U.S. Census Bureau, using the

July 1, 2003, and July 1, 2004, sets of state population estimates and reflect Census 2000 data.

3

NSAID is non-steroidal anti-inflammatory drug.

4

ACE is angiotensin converting enzyme.

NOTES: Figures are annual averages.
Page 28 [ Series 13, No. 163

Table 11. Annual population rates for the top 20 specific therapeutic classes of drug mentions at ambulatory care visits, by selected patient

and provider characteristics: United States, 2003–04

Patient race Expected source of payment MSA2 status

Private

Specific therapeutic class1 Total White Black insurance Medicare Medicaid Uninsured MSA Not MSA

Number of occurrences per 1,000 persons3

NSAID4 ................... 390.3 392.1 474.1 289.7 616.8 535.9 186.0 392.2 379.4

Antidepressants .............. 310.9 344.5 207.0 237.7 564.8 345.9 174.1 318.9 269.0

Antiasthmatics and bronchodilators . . 278.0 284.1 306.1 211.1 517.1 451.3 89.1 285.8 237.6

Antihistamines ............... 276.9 283.7 275.0 244.2 332.9 389.4 107.0 282.4 246.2

Narcotic analgesics ............ 273.5 284.1 299.4 179.5 445.5 400.3 201.8 268.7 299.2

Non-narcotic analgesics ......... 266.6 266.8 315.3 158.3 737.9 400.2 93.3 260.7 296.9

Antipyretics ................. 243.7 242.6 293.5 144.8 683.7 365.0 81.3 240.2 262.0

Antihypertensive agents ......... 242.5 241.2 306.7 157.0 877.9 117.1 52.3 245.1 228.6

Hyperlipidemia ............... 241.7 248.7 227.9 165.2 823.0 135.9 36.4 246.8 214.1

Acid and peptic disorders ........ 237.4 240.1 234.9 156.5 677.1 254.5 73.2 237.1 238.8

Antiarthritics ................ 232.6 238.4 250.2 142.3 803.1 157.1 48.8 228.6 254.3

Blood glucose regulators......... 207.5 199.1 287.5 129.5 661.8 205.5 56.4 204.5 222.7

Vaccines and antisera .......... 192.0 195.3 175.9 158.0 162.3 443.2 42.8 206.4 117.2

Diuretics................... 176.4 176.2 236.3 83.4 755.2 119.7 43.4 173.9 188.6

Vitamins and minerals .......... 173.5 181.8 151.3 116.7 490.2 203.1 45.4 177.1 156.3

ACE5 inhibitors............... 173.2 175.5 202.5 102.3 641.7 119.5 38.7 172.2 178.0

Beta blockers................ 161.9 164.0 186.8 93.1 630.3 91.3 30.7 165.1 144.4

Penicillins .................. 156.3 155.0 164.2 137.7 101.6 312.2 67.8 159.1 141.6

Adrenal corticosteroids .......... 141.7 147.4 144.2 109.4 268.2 180.2 52.5 144.5 127.1

Anticonvulsants .............. 131.3 140.3 116.2 79.0 261.5 227.5 75.4 134.4 115.5

Standard error of rate

NSAID4 ................... 15.7 17.8 27.9 13.8 39.7 44.5 13.3 17.0 46.0

Antidepressants .............. 14.3 16.4 19.2 12.9 43.4 30.8 21.0 16.7 33.5

Antiasthmatics and bronchodilators . . 17.7 19.7 29.5 17.3 47.8 37.8 8.5 20.5 28.7

Antihistamines ............... 14.3 16.0 21.3 14.5 26.0 35.2 8.1 16.7 30.3

Narcotic analgesics ............ 11.2 12.9 16.0 9.4 27.8 28.0 11.4 12.6 34.2

Non-narcotic analgesics ......... 14.4 15.6 26.7 10.8 51.4 40.5 8.2 15.3 43.9

Antipyretics ................. 13.8 14.8 27.9 10.4 48.9 38.1 7.1 14.7 41.4

Antihypertensive agents ......... 15.1 16.7 35.1 12.1 66.3 18.3 6.8 17.1 38.6

Hyperlipidemia ............... 15.5 17.3 27.4 13.1 60.8 17.5 6.2 17.7 32.1

Acid and peptic disorders ........ 13.1 14.7 18.7 10.8 50.2 23.9 8.2 14.9 36.1

Antiarthritics ................ 14.2 16.3 24.1 11.7 54.0 17.7 6.3 14.7 48.1

Blood glucose regulators......... 14.4 15.4 32.4 10.8 58.4 28.8 7.5 15.1 45.9

Vaccines and antisera .......... 12.6 13.9 18.4 13.2 29.3 50.0 5.8 14.2 22.6

Diuretics................... 10.5 11.4 22.5 6.9 54.9 13.6 6.4 11.6 30.9

Vitamins and minerals .......... 11.8 13.5 18.6 9.7 46.2 29.2 6.5 13.4 26.9

ACE5 inhibitors............... 10.5 12.0 20.1 8.5 45.5 14.9 5.7 11.4 30.0

Beta blockers................ 9.6 10.7 17.8 6.7 45.5 11.3 4.0 11.1 20.4

Penicillins .................. 8.6 9.0 14.6 8.8 13.5 28.1 6.3 9.7 19.8

Adrenal corticosteroids .......... 7.4 8.4 11.7 8.2 19.9 15.7 6.1 8.7 17.4

Anticonvulsants .............. 7.3 8.4 11.3 5.4 20.1 22.4 10.3 8.3 17.9

1

Based on the standard drug classification used in the National Drug Code Directory, 1995 edition (NDC) (12). In the NDC, therapeutic classes are assigned to drugs using 21 broad categories (2-digit

level), and into specific categories (4-digit level) within each broad group. In NAMCS and NHAMCS, up to three therapeutic classes can be coded for each drug. Drugs are counted in each class in

which they occur.

2

MSA is metropolitan statistical area.

3

Estimates of the civilian noninstitutionalized population used in computing rates by race are from special tabulations developed by the Population Division, U.S. Census Bureau, using the July 1, 2003,

and July 1, 2004, sets of state population estimates and reflect Census 2000 data. Denominators for primary expected source of payment rates are from the 2003 and 2004 estimates of health

coverage from the National Health Interview Survey, NCHS, adjusted to Census 2000-based population estimates. Denominators for metropolitan and nonmetropolitan statistical area rates are based

on data from the 2003 and 2004 National Health Interview Survey, NCHS, adjusted to the U.S. Census Bureau definition of core-based statistical areas as of December 2003.

4

NSAID is nonsteroidal anti-inflammatory drug.

5

ACE is angiotensin converting enzyme.

NOTES: Figures are annual averages. Races other than white and black are not shown because of small sample sizes.
Series 13, No. 163 [ Page 29

Table 12. Annual percent distribution and rate of the generic-equivalents most frequently provided, prescribed, or continued at ambulatory

care visits: United States, 1993–94 and 2003–04

Number of

Percent mentions per

1993–94 distribution 100 visits Specific therapeutic class1

All drugs................... 100.0 128.8 . . .

Amoxicillin.................. 3.3 4.3 Penicillins

Ibuprofen .................. 2.2 2.8 NSAID2

Acetaminophen .............. 2.1 2.7 Non-narcotic analgesics; antipyretics

Albuterol................... 1.8 2.4 Antiasthmatics and bronchodilators

Furosemide ................. 1.3 1.6 Diuretics

Erythromycin ................ 1.2 1.5 Lincosamides and macrolides

Aspirin .................... 1.1 1.5 Non-narcotic analgesics; antiarthritics; antipyretics

Prednisone ................. 1.1 1.4 Adrenal corticosteroids

Estrogens .................. 1.1 1.4 Estrogens and progestins

Digoxin ................... 1.0 1.3 Cardiac glycosides

All other ................... 83.8 107.9 . . .

2003–04

All drugs................... 100.0 158.7 . . .

Ibuprofen .................. 2.3 3.6 NSAID2

Aspirin .................... 1.8 2.8 Non-narcotic analgesics; antiarthritics; antipyretics

Acetaminophen .............. 1.7 2.7 Non-narcotic analgesics; antipyretics

Atorvastatin calcium............ 1.6 2.5 Hyperlipidemia

Acetaminophen with hydrocodone . . . 1.6 2.5 Narcotic analgesics

Albuterol................... 1.5 2.5 Antiasthmatics and bronchodilators

Amoxicillin.................. 1.5 2.3 Penicillins

Levothyroxine ............... 1.2 1.9 Thyroid and antithyroid

Azithromycin ................ 1.1 1.7 Lincosamides and macrolides

Metoprolol.................. 1.1 1.7 Beta blockers

All other ................... 84.6 134.5 . . .

...Category not applicable.

1

Based on the standard drug classification used in the National Drug Code Directory, 1995 edition (NDC) (12). In the NDC, therapeutic classes are assigned to drugs using 21 broad categories (2-digit

level), and into specific categories (4-digit level) within each broad group. In NAMCS and NHAMCS, up to three therapeutic classes can be coded for each drug. Drugs are counted in each class in

which they occur.

2

NSAID is nonsteroidal anti-inflammatory drug.

NOTE: For this table, 2003–04 data were limited to the first five out of eight possible drug entries for each sampled visit. This was done in order to be consistent with the 1993–94 data collection, in

which a maximum of five drugs could be coded.
Page 30 [ Series 13, No. 163

Appendix I

Technical Notes

Data collection

The National Ambulatory Medical

Care Survey (NAMCS) and National

Hospital Ambulatory Medical Care

Survey (NHAMCS) data collection is

authorized under Section 308(d) of the

Public Health Service Act (42 United

States Code Section 306 [242k].

Participation is voluntary.

For the 2003 NAMCS, 3,000

physicians were selected from the

masterfiles of the American Medical

Association and American Osteopathic

Association. Of these, 2,007 were

in-scope, or eligible to participate in the

survey. Sampled physicians were asked

to complete Patient Record forms

(PRFs) for a systematic random sample

of office visits occurring during a

randomly assigned 1-week reporting

period. A total of 1,407 physicians

participated in the survey, 65 of them

minimally (defined as submitting fewer

than 50 percent of their expected

number of PRFs). The physician

response rate was 67 percent, and

25,288 PRFs were submitted. Data were

collected from December 30, 2002,

through December 30, 2003. It should

be noted that response rates for both

NAMCS and NHAMCS do not include

minimal responders.

For the 2004 NAMCS, 1,961

physicians of the 3,000 sampled were

in-scope; 1,372 of them participated,

103 of them at a minimal level. The

physician response rate was 65 percent,

and 25,286 PRFs were submitted; data

collection occurred from December 29,

2003, through December 26, 2004.

NHAMCS utilizes a fixed panel of

600 hospitals. To preclude hospitals

participating during the same time

period each year, the sample was

randomly divided into 16 subsets of

approximately equal size. Each subset

was assigned to 1 of 16 4-week

reporting periods beginning December 2,

1991, which continue to rotate across

each survey year. Therefore, the entire

sample does not participate in a given

year, and each hospital is inducted

approximately once every 15 months.

Hospital staff were asked to complete

PRFs for a systematic random sample of

patient visits occurring during a

randomly assigned 4-week reporting

period.

The 2003 NHAMCS collected data

from December 30, 2002, through

December 28, 2003, and consisted of a

sample of 546 hospitals, of which 443

had eligible EDs. Of these, 406 EDs

participated, 1 of them minimally, for an

unweighted ED participation rate of

91 percent. Of the 506 emergency

service areas (ESAs) selected from the

emergency departments, 475 provided

data, 3 of them at a minimal level. The

ESA response rate was 93 percent, and

the overall ED response rate was

85 percent. In all, 40,253 ED PRFs were

collected.

Of the 546 hospitals sampled in

2003, 272 had eligible outpatient

departments. Of these 236 participated,

10 at a minimal level, for an unweighted

OPD participation rate of 83 percent. Of

the 1,087 clinics selected from the

in-scope OPDs, 983 participated, 35 at a

minimal level. The clinic response rate

was 87 percent, for an overall OPD

response rate of 73 percent. In all,

34,492 OPD PRFs were collected.

The 2004 NHAMCS collected data

from December 29, 2003, through

December 26, 2004, and consisted of a

sample of 464 hospitals, of which 397

were in scope and had eligible EDs. Of

these, 365 EDs participated, for an

unweighted ED response rate of

92 percent. Of the 467 ESAs selected

from the EDs, 457 provided data, 5 of

them minimally, and 1 ESA saw no

patients during the reporting period but

was counted as a respondent. The ESA

response rate was 97 percent, and the

overall ED response rate was 89 percent.

In all, 36,589 ED PRFs were collected.

Of the 464 hospitals sampled in

2004, 250 had eligible OPDs, of which

217 participated, for an unweighted

OPD participation rate of 87 percent. Of

the 1,108 clinics selected from the

OPDs, 984 provided data, 29 of them at

a minimal level. An additional 6

responding clinics saw no patients

during the reporting period. The clinic

response rate was 87 percent, for an

overall OPD response rate of 75 percent.

In all, 31,783 OPD PRFs were collected.

The U.S. Census Bureau, acting as

the data collection agent for both

surveys, provided training to field

representatives (FRs) throughout the

Nation who, in turn, oversaw data

collection at physician offices and

hospitals. FRs contacted physicians and

hospitals for induction into the surveys

after NCHS mailed an advance letter

notifying the providers of their selection

in the survey. For the NAMCS, medical

staff most often provided the

information requested on the PRFs

(Appendix III); however, in some cases,

FRs performed data abstraction from

medical records. For the NHAMCS, FR

abstraction was the predominant method

of data collection. Neither the patient’s

name nor address was collected.

Confidentiality of the data collected in

the survey is protected under the

Privacy Act, Public Health Service Act,

and Title 42 of the United States Code,

Section 242m(d).

Estimation

Estimates from the 2003 and 2004

NAMCS and NHAMCS were derived

by multistage estimation procedures that

produce essentially unbiased estimates.

The estimation for NAMCS has four

basic components: 1) inflation by

reciprocals of the probabilities of

selection; 2) adjustment for

nonresponse; 3) a ratio adjustment to

fixed totals; and 4) weight smoothing.

These are described in more detail

elsewhere (20,21). However, certain

changes were made to the NAMCS and

NHAMCS nonresponse adjustments in

2003 and 2004; these changes are

described below.

Estimates from NAMCS data are

typically adjusted to account for sample

physicians who were in scope but did

not participate in the study. This

adjustment is calculated to minimize the

impact of nonresponse on final

estimates. The weights of visits for

physicians similar to the nonrespondent

physicians are inflated to account for

visits represented by the nonrespondent
Series 13, No. 163 [ Page 31

physicians. For this purpose, physicians

were judged similar if they had the

same specialty designation and practiced

in the same primary sampling unit (2).

Beginning with 2003 data, the

adjustment for nonresponding physicians

differs from the adjustment used in prior

years. Previously the adjustment

accounted for nonresponse by physician

specialty, geographic region, and

metropolitan statistical area status. The

revised nonresponse adjustment also

accounts for nonresponse from

physicians by practice size, as measured

by number of weekly visits, and for

variability in number of weeks that

participating physicians saw patients

during the year.

Previously, these characteristics

were assumed to be the same for

physicians providing patient encounter

information and those not providing

such information. However, research

done for the first time with 2003 data

showed that these two assumptions are

not always true. In general, the weekly

visit volume for non-PRF physicians

was larger than for PRF physicians.

Also, physicians who saw no patients

during their sample week tended to see

patients fewer weeks annually than did

physicians who saw patients during their

week. To minimize understatement (and

in some cases, overstatement) of visits,

the nonresponse adjustment factor was

revised to include information on the

number of weeks physicians actually

practiced during a typical year and the

number of visits physicians reported

during a week. Both data items were

collected for responding and

nonresponding physicians during the

induction interview starting with the

2001 survey.

The 2003 weight with the revised

nonresponse adjustment increased the

overall visit estimate by 12 percent over

the same estimate obtained using the

original weight. For this reason, 2003

and 2004 visit estimates are not

comparable to visit estimates computed

using the previous weighting strategy.

For more information, including

recommendations for researchers

analyzing trend data, please see the

2003 NAMCS summary (2).

Beginning with 2004 data, changes

were made to the nonresponse

adjustment factor to account for the

seasonality of the reporting period. Extra

weights for nonresponding physicians

were shifted to responding physicians in

reporting periods within the same

quarter of the year. The shift in

nonresponse adjustment did not

significantly affect any of the overall

annual estimates.

The estimation for NHAMCS has

three basic components: 1) inflation by

reciprocals of the sampling selection

probabilities; 2) adjustment for

nonresponse; and 3) a population

weighting ratio adjustment. The

population weighting ratio adjustment

for OPD estimates was replaced by an

adjustment which controls for effects of

rotating hospital sample panels into and

out of the sample each year. (The full

NHAMCS hospital sample is partitioned

into 16 panels that are rotated into the

sample over 16 periods of 4 weeks each

so that only 13 panels are used in any

single year.) The sampling weights of

some OPDs were permanently trimmed

to prevent single OPDs from

contributing more than 15 percent of

their region’s total to OPD visit

estimates.

NHAMCS data were adjusted to

account for two types of nonresponse.

The first type occurred when a hospital

refused to provide information about its

ED or OPD that was publicly known to

exist. In this case, the weights of visits

to hospitals similar to the nonrespondent

hospitals were inflated to account for

visits represented by the nonrespondent

hospitals. Beginning with 1998 data,

hospitals were judged to be similar if

they were in the same region and,

except in the West, if they had the same

MSA status (in an MSA vs. not in an

MSA). Similarity of hospitals also

required being in the same ownership

control group (voluntary nonprofit

compared with other). This adjustment

was made separately by department

type.

The second type of nonresponse

occurred when a sample ESA within a

respondent hospital failed to provide

completed PRFs for a sample of patient

visits. In the ED, the weights of visits

from responding ESAs were inflated to

account for visits to similar

nonresponding ESAs, where ESAs were

judged to be similar if they were in the

same region. Except in the West, ESA

similarity also required having the same

MSA status, and, in MSAs, being in the

same ownership control group

(voluntary nonprofit vs. other).

For the OPD, weights of visits from

responding OPD clinics were inflated to

account for visits to similar

nonresponding OPD clinics, where OPD

clinics were judged to be similar if they

were in the same region, clinic type, and

ownership control group (voluntary

nonprofit vs. other). There were six

OPD clinic types: general medicine,

pediatrics, surgery, obstetrics and

gynecology, alcohol and/or substance

abuse, and other OPD clinic. Beginning

with 1998 data, formation of groups of

similar clinics also considered the MSA

status of the clinic (in an MSA or not in

an MSA) with the following two

exceptions: in the West, MSA status was

not considered; and in non-MSA clinics

in the other three regions, ownership

control group (voluntary nonprofit

compared with other) was not

considered.

Beginning with 2004 data, changes

were made to the nonresponse

adjustment factor to account for the

seasonality of the reporting period. Extra

weights for nonresponding hospital

OPDs and EDs were shifted to

responding OPDs and EDs in reporting

periods within the same quarter of the

year. The shift in nonresponse

adjustment did not significantly affect

any of the overall annual estimates.

Sampling Errors

The standard error is primarily a

measure of the sampling variability that

occurs by chance when only a sample,

rather than an entire universe, is

surveyed. The standard error also

reflects part of the measurement error,

but does not measure any systematic

biases in the data. The chances are 95

out of 100 that an estimate from the

sample differs from the value that would

be obtained from a complete census by

less than twice the standard error.

The standard errors used in tests of

significance for this report were

calculated using SUDAAN software.
Page 32 [ Series 13, No. 163

SUDAAN computes standard errors by

using a first-order Taylor approximation

of the deviation of estimates from their

expected values. A description of the

software and the approach it uses has

been published (19). The relative

standard error (RSE) of an estimate is

obtained by dividing the standard error

by the estimate itself. The result is then

expressed as a percent of the estimate.

It is recommended that statistical

software (such as SUDAAN, SAS,

SPSS, or Stata) be used to compute

variances for complex survey data.

When it is not feasible to use statistical

software, one may calculate approximate

RSEs for aggregate estimates using

generalized variance curve parameters as

described in the NAMCS and NHAMCS

public use file documentation (20,21).

These publications contain information

for computing approximate RSEs for

single years of NAMCS and NHAMCS

data from 2003 and 2004. For estimates

based on two or more years of data, or

when combining data from multiple

settings across one or more years, please

consult the Ambulatory Care Statistics

Branch at 301-458-4600 for more

information about approximating RSEs

using generalized variance curves.

Nonsampling errors

As in any survey, results are subject

to both sampling and nonsampling

errors. Nonsampling errors include

reporting and processing errors, as well

as biases due to nonresponse and

incomplete response. The magnitude of

the nonsampling errors cannot be

computed. However, these errors were

kept to a minimum by procedures built

into the operation of the survey. To

eliminate ambiguities and encourage

uniform reporting, attention was given

to the phrasing of questions, terms, and

definitions. Also, most data items and

survey procedures were pretested.

Quality control procedures and

consistency and edit checks reduced

errors in data coding and processing.

The error rate (which includes coding

and keying errors) ranged from 0.0 to

1.5 for both surveys.

Adjustments for item nonresponse

include the following: Missing data for

several of the items mentioned in this

report were imputed by randomly

assigning a value from a PRF with

similar characteristics. These items

include patient’s birth date (used to

determine age), sex, race, and ethnicity.

In the NAMCS, imputations were based

on physician specialty, geographic

region, and 3-digit ICD-9-CM code for

primary diagnosis. In the NHAMCS,

imputations for ED data were based on

ED size, geographic region, immediacy

with which patient should be seen, and

3-digit ICD-9-CM code for primary

diagnosis. For OPD data, imputations

were based on geographic region, OPD

size by clinic, and 3-digit ICD-9-CM

code for primary diagnosis. Beginning

in 2004, the imputation for ethnicity

was revised to take into account state

rather than region.

Tests of Significance

In this report, the determination of

statistical inference is based on the X2

test and the two-tailed t-test. The

Bonferroni inequality was used to

establish the critical value for

statistically significant differences (0.05

level of significance) based on the

number of possible comparisons within

a particular variable (or combination of

variables) of interest. Terms relating to

differences such as ‘‘greater than’’ or

‘‘less than’’ indicate that the difference

is statistically significant. A lack of

comment regarding the difference

between any two estimates does not

mean that the difference was tested and

found to be not significant. Chi-square

tests were performed using the

SUDAAN routine PROC CROSSTAB,

which takes into account the complex

sample designs used in the NAMCS and

NHAMCS.

A weighted least-squares regression

analysis was used to determine the

significance of the relationship between

age and drug mention rates. In this

modified least-squares regression, each

estimate is weighted by the inverse of

the standard error (22).

Published and Flagged

Estimates

Estimates are not presented unless a

reasonable assumption regarding their

probability distributions is possible on

the basis of the Central Limit Theorem.

The Central Limit Theorem states that,

given a sufficiently large sample size,

the sample estimate approximates the

population estimate and, upon repeated

sampling, its distribution would be

approximately normal.

In this report, estimates are not

presented if they are based on fewer

than 30 cases in the sample data; only

an asterisk (*) appears in the tables.

Estimates based on 30 or more cases are

asterisked only if the RSE of the

estimate exceeds 30 percent.

In addition, estimates in this report

have been rounded to the nearest

thousand. Consequently, summed figures

may not always add to totals. Rates and

percentages were calculated from

original unrounded figures and do not

necessarily agree with percentages

calculated from rounded data.

Physician specialty groupings

Information on physician specialty

is obtained from the American Medical

Association (AMA) and the American

Osteopathic Association (AOA) as part

of the initial sampling process and is

verified with the physician at the time

of the induction interview. For

tabulation purposes, doctors of

osteopathy are grouped with doctors of

medicine according to their selfdesignated practice specialty.

In this report, office visit data are

divided into three settings, according to

the self-designated practice specialty of

the sampled physician. These data are

presented in terms of visits to the

offices of primary care physicians,

surgical specialists, and medical

specialists, using a classification

suggested by the AMA (18). Table I

shows the specialties used to define

each category.

Race and ethnicity

The 2003–04 NAMCS and

NHAMCS collected race data according

to standards issued by the Office of

Management and Budget in 1999 to

promote comparability of data among

federal data sources and so that more

than one race could be recorded per
Series 13, No. 163 [ Page 33

Table I. Reclassification of physician specialty for use with National Ambulatory Medical Care Survey data

Physician specialty group Physician specialty

Primary care specialties ....... Family practice, geriatric medicine (family practice), sports medicine (family practice), general practice, internal medicine,

internal medicine (pediatrics), adolescent medicine (internal medicine), geriatric medicine (internal medicine), adolescent

medicine, pediatrics, pediatric sports medicine, gynecology, maternal and fetal medicine, obstetrics and gynecology,

obstetrics.

Surgical specialties ......... General surgery, gynecological oncology, critical care medicine (obstetrics and gynecology), hand surgery (orthopedic

surgery), adult reconstructive orthopedics, foot and ankle orthopedics, musculoskeletal oncology, pediatric orthopedics,

orthopedic surgery, sports medicine (orthopedic surgery), orthopedic surgery of the spine, orthopedic trauma, urology,

pediatric urology, ophthalmology, pediatric ophthalmology, otology-neurotology, otology, otolaryngology, pediatric

otolaryngology, abdominal surgery, cardiovascular surgery, colon and rectal surgery, cardiothoracic surgery, craniofacial

surgery, critical care surgery, dermatologic surgery, facial plastic surgery, head and neck surgery, hand surgery (plastic

surgery), hand surgery (surgery), critical care (neurological surgery), neurological surgery, pediatric surgery (neurology),

pediatric cardiothoracic surgery, pediatric surgery, plastic surgery, surgical oncology, thoracic surgery, transplant surgery,

traumatic surgery, vascular surgery.

Medical specialties ......... Critical care pediatrics, developmental-behavioral pediatrics, neurodevelopmental disabilities, neonatal-perinatal medicine,

pediatric allergy, pediatric cardiology, pediatric endocrinology, pediatric infectious diseases, pediatric pulmonology, medical

toxicology (pediatrics), pediatric emergency medicine, pediatric gastroenterology, pediatric hematology/oncology, pediatric

nephrology, pediatric rehabilitation medicine, pediatric rheumatology, reproductive endocrinology, cardiovascular diseases,

dermatology, psychiatry, addiction psychiatry, child psychiatry, forensic psychiatry, psychoanalysis, geriatric psychiatry,

neurology, child neurology, clinical neurophysiology, neurology (diagnostic radiology), addiction medicine, aerospace medicine,

allergy, allergy and immunology, allergy and immunology/diagnostic laboratory immunology, cardic electrophysiology, clinical

genetics, clinical biochemical genetics, clinical cytogenetics, clinical molecular genetics, critical care medicine, dermatological

immunology/diagnostic laboratory immunology, diabetes, emergency medicine, epidemiology, endocrinology, gastroenterology,

general preventive medicine, hematology, hepatology, hematology/oncology, infectious diseases, internal medicine/diagnostic

laboratory immunology, immunology, interventional cardiology, legal medicine, medical management, medical genetics,

medical toxicology (emergency medicine), medical toxicology (preventive medicine), medical oncology, nephrology, nutrition,

occupational medicine, osteopathic manipulative medicine, pain medicine, palliative medicine, pediatric emergency medicine

(emergency medicine), pediatric/diagnostic laboratory immunology, pharmaceutical medicine, public health, public health and

general preventive medicine, clinical pharmacology, physical medicine and rehabiliation, pulmonary critical care medicine,

pulmonary diseases, sports medicine (emergency medicine), sports medicine (physical medicine and rehabilitation),

rheumatology, spinal cord injury, sleep medicine, undersea medicine, vascular medicine.

person (23). Respondents could check

multiple categories for each patient from

these groups: White, Black or African

American, Asian, Native Hawaiian or

other Pacific Islander, and American

Indian or Alaska Native. Estimates for

specific race categories reflect visits

where only a single race was reported.

For this report, estimates for the six race

categories (White, Black or African

American, Asian, Native Hawaiian or

other Pacific Islander, American Indian

or Alaska Native, and persons of

multiple race) are presented in Tables 2

and 3, while data for some of these race

groups are presented in Figure 3 and

Table 11. Data for all six race groups

are not shown in Figure 3 and Table 11

because of small sample sizes. Because

of the difference between single- and

multiple-race reporting, race-specific

estimates prior to 1999 are not strictly

comparable with those from 1999 and

subsequent years, when this method of

collecting race data was implemented in

NAMCS and NHAMCS. However, from

1999 to the present, only a small

proportion of records had multiple races

indicated.

Race and Hispanic origin are

collected separately in NAMCS and

NHAMCS in accordance with OMB

standards. Consequently, all race

categories include visits by persons of

Hispanic and not Hispanic origin.

Persons of Hispanic origin may be of

any race.

Population Figures and Rate

Calculation

The population figures used in

calculating 2003–04 visit rates by age,

sex, race, ethnicity, geographic region,

MSA status, and insurance status are

shown in Tables II and III. The

estimates of age, sex, race, ethnicity,

and geographic region reflect Census

2000–based postcensal estimates of the

civilian noninstitutional population of

the United States. They are special

tabulations developed by the Population

Division, U.S. Census Bureau, from the

July 1, 2003, and July 1, 2004, set of

state population estimates. Population

estimates of MSA status and insurance

status are based on data from the 2003

and 2004 National Health Interview

Surveys, National Center for Health

Statistics (NCHS), which also reflect the

civilian noninstitutional population of

the United States. NHIS estimates for

2003 and 2004 were developed using

Census 2000–based data. All population

estimates shown are 2-year averages for

2003 and 2004.

Changes to Ambulatory Care

Drug Database and Therapeutic

Class of Drugs

Since drug data were first collected

in 1980, NCHS has provided drug

characteristics, including therapeutic

class of drug based on the National

Drug Code Directory (12), for each drug

entered on the Patient Record form

(PRF). Through 2001, only a single

therapeutic class was included for each

drug, although drugs may have multiple

therapeutic classes, and it was not

necessarily the case that the class listed

for a particular drug was also the same

as its intended therapeutic purpose at the

medical visit. Because of the

complexities involved with assigning

therapeutic classes for drugs, the
Page 34 [ Series 13, No. 163

Table II. Population estimates used in computing annual visit rates for the National Ambulatory Medical Care Survey and National Hospital

Ambulatory Medical Care Survey, by age, race, sex, and ethnicity: United States, 2003–04

All Under 15 15–24 25–44 45–64 65–74 75 years

Characteristic ages years years years years years and over

Sex Population estimate1

All races ....................... 286,947,862 60,728,632 40,369,442 82,178,384 69,205,345 18,156,364 16,309,696

Male ........................ 140,207,808 31,067,772 20,367,117 40,591,327 33,573,892 8,276,136 6,331,565

Female ....................... 146,740,054 29,660,861 20,002,325 41,587,057 35,631,453 9,880,228 9,978,131

Race

White ......................... 231,403,767 46,394,226 31,477,464 65,550,953 57,805,580 15,649,327 14,526,219

Male ........................ 114,009,790 23,790,255 16,018,126 32,926,785 28,379,706 7,211,861 5,683,059

Female ....................... 117,393,977 22,603,971 15,459,338 32,624,168 29,425,875 8,437,466 8,843,160

Black or African American ............. 35,925,710 9,422,169 5,851,792 10,338,647 7,441,684 1,661,432 1,209,987

Male ........................ 16,655,223 4,778,919 2,822,881 4,610,956 3,338,062 686,668 417,738

Female ....................... 19,270,487 4,643,250 3,028,911 5,727,692 4,103,622 974,764 792,249

American Indian or Alaska Native ........ 2,751,939 709,761 498,565 820,285 551,280 105,277 66,773

Male ........................ 1,362,563 360,245 251,991 409,156 266,089 48,539 26,545

Female ....................... 1,389,376 349,516 246,575 411,129 285,191 56,738 40,228

Asian ......................... 12,053,839 2,346,471 1,674,587 4,318,682 2,705,796 600,992 407,313

Male ........................ 5,821,792 1,195,789 845,725 2,091,077 1,257,866 265,448 165,889

Female ....................... 6,232,047 1,150,682 828,862 2,227,605 1,447,930 335,544 241,424

Native Hawaiian or other Pacific Islander . . . 491,382 123,083 88,609 163,095 89,004 17,338 10,254

Male ........................ 247,233 62,948 45,180 82,661 44,025 8,216 4,205

Female ....................... 244,149 60,136 43,429 80,435 44,979 9,122 6,049

More than one race reported ........... 4,321,227 1,732,924 778,426 986,723 612,003 122,000 89,152

Male ........................ 2,111,208 879,617 383,216 470,694 288,146 55,405 34,131

Female ....................... 2,210,019 853,307 395,211 516,029 323,857 66,595 55,021

Ethnicity

Hispanic or Latino.................. 40,089,664 11,832,596 6,887,270 13,271,387 6,030,483 1,234,804 833,124

Male ........................ 20,526,263 6,047,788 3,635,107 7,018,747 2,949,268 547,280 328,074

Female ....................... 19,563,402 5,784,809 3,252,163 6,252,640 3,081,216 687,524 505,051

Not Hispanic or Latino ............... 246,858,198 48,896,036 33,482,172 68,906,997 63,174,862 16,921,560 15,476,572

Male ........................ 119,681,546 25,019,984 16,732,010 33,572,580 30,624,625 7,728,856 6,003,492

Female ....................... 127,176,652 23,876,052 16,750,162 35,334,417 32,550,238 9,192,704 9,473,080

1

Estimates are of the civilian noninstitutionalized population and are from special tabulations developed by the Population Division, U.S. Census Bureau, using July 1, 2003, and July 1, 2004, sets of

state population estimates and reflect Census 2000 data.

decision was made, beginning with the

2002 data release, to include up to three

therapeutic classes for each drug entry

on the PRF.

For this report, the drug

characteristics updated for use with

2004 data were applied to 1993–94 data

as well so that comparisons could be

made between the two time periods,

1993–94 and 2003–04. As a

consequence, the totals shown in Table 6

exceed the actual sum of drugs

provided, prescribed, or continued at

ambulatory care visits since each drug

may be assigned as many as three

therapeutic classes.

Researchers doing trend analysis

with NAMCS and NHAMCS drug data

are advised to download the Drug

Characteristics file, available at the

Ambulatory Health Care Data website

(http://www.cdc.gov/nchs/namcs.htm).

The characteristics from this file can be

applied by matching drug codes to

previous years of data to get the most

accurate results when doing analysis of

drug trends. A file layout and sample

SAS code for applying drug

characteristics from the file to previous

years of public use data is also available

for downloading.

The current Drug Characteristics

file contains a number of updates and

revisions. Over the last few years, many

drugs had ingredient lists reviewed, and

non active ingredients were removed.

Duplicate codes caused by misspellings

or other variant entries were eliminated,

and incorrect codes (for example, for

non medications) were removed. The

Drug Characteristics file is updated

annually, and is generally available

following the release of public-use files

for the survey year in question.

Tables 8, 9, and 12 which show

ranked generic substances occurring in

drugs provided, prescribed, or continued

at ambulatory care visits, utilize a

format for generic substances that is

slightly modified from the results one

would get using the current Drug

Characteristics file. In the ambulatory

care drug database (and the Drug

Characteristics file), certain substances

can appear in both generic and salt

forms, such as albuterol and albuterol

sulfate, or in forms such as hydrocodone

and hydrocodone bitartrate. With the

advent of the 2002 Drug Characteristics

file, the drug database staff also
Series 13, No. 163 [ Page 35

Table III. Population estimates used in computing annual visit rates for the National

Ambulatory Medical Care Survey and National Hospital Ambulatory Medical Care Survey,

by geographic region, metropolitan statistical area status, and insurance status:

United States, 2003–04

Population

Characteristic estimate

Geographic region1

Northeast ......................... 53,663,348

Midwest .......................... 64,541,714

South............................ 102,917,535

West ............................ 65,825,265

MSA status2

MSA ............................ 240,805,071

Non-MSA ......................... 46,142,791

Insurance status3

Private insurance .................... 193,071,855

Medicare.......................... 35,595,073

Medicaid .......................... 30,284,147

Uninsured ......................... 41,496,808

1

Estimates are of the civilian noninstitutionalized population of the United States and are from special tabulations developed by

the Population Division, U.S. Census Bureau, using July 1, 2003, and July 1, 2004, sets of state population estimates and reflect

Census 2000 data.

2

MSA is metropolitan statistical area. Estimates are based on data from the 2003 and 2004 National Health Interview Surveys,

NCHS, adjusted to the U.S. Census Bureau definition of core-based statistical areas as of December 2003.

3

Estimates are from the 2003 and 2004 National Health Interview Surveys, NCHS, adjusted to Census 2000–based population

estimates.

formulated a list of generic codes which

collapses different formulations for

generic substances into aggregate

categories. Therefore, in Tables 8, 9, and

12, albuterol is displayed but actually

reflects a combination of albuterol and

albuterol sulfate in the original survey

data. The aggregated format for generic

substances is also available at the

Ambulatory Health Care Data website.

For more information, contact the

Ambulatory Care Statistics Branch.
Page 36 [ Series 13, No. 163

Appendix II

Definition of Terms

Drug mention—A drug mention is

the physician’s entry on the Patient

Record form of a pharmaceutical

agent—by any route of administration—

for prevention, diagnosis, or treatment.

Generic as well as brand-name drugs are

included, as are nonprescription and

prescription drugs. Along with all new

drugs, the physician also records

continued medications if the patient was

specifically instructed during the visit to

continue the medication. Physicians may

report up to eight medications per visit.

Drug mention rate—For this report,

a drug mention rate is the number of

drug mentions per 100 office visits. It

allows one to compare prescribing rates

while holding the number of visits

constant.

Drug visit—A drug visit is a visit at

which medication was prescribed or

provided by the physician.

Emergency department (ED)—An

ED is a hospital facility that provides

unscheduled outpatient services to

patients whose conditions require

immediate care and that is staffed 24

hours a day. If an ED provided

emergency services in different areas of

the hospital, all of these areas were

selected with certainty into the sample.

Off-site emergency departments that are

open less than 24 hours are included if

staffed by the hospital’s emergency

department.

Emergency service area—An

emergency service area is the smallest

administrative unit of an ED where

separate patient statistics are kept. It

may be located on hospital grounds or

operated off site by the hospital.

Federal control status— Federal

control status refers to the classification

of a substance according to the

Controlled Substances Act (CSA), Title

II of the Comprehensive Drug Abuse

Prevention and Control Act of 1970.

CSA places all substances that are

regulated under existing federal law into

one of five schedules. This placement is

based on the substance’s medicinal

value, harmfulness, and potential for

abuse or addiction. The schedules are as

follows:

+ Schedule I: (A) The drug or

other substance has a high potential for

abuse. (B) The drug or other substance

has no currently accepted medical use in

treatment in the United States. (C) There

is a lack of accepted safety for use of

the drug or other substance under

medical supervision.

+ Schedule II: (A) The drug or

other substance has a high potential for

abuse. (B) The drug or other substance

has a currently accepted use in treatment

in the United States or a currently

accepted medical use with severe

restrictions. (C) Abuse of the drug or

other substance may lead to severe

psychological or physical dependence.

+ Schedule III: (A) The drug or

other substance has a potential for abuse

less than the drugs or other substances

on schedules I and II. (B) The drug or

other substance has a currently accepted

medical use in treatment in the United

States. (C) Abuse of the drug or other

substance may lead to moderate or low

physical dependence or high

psychological dependence.

+ Schedule IV: (A) The drug or

other substance has a low potential for

abuse relative to the drugs or other

substances in schedule III. (B) The drug

or other substance has a currently

accepted medical use in treatment in the

United States. (C) Abuse of the drug or

other substance may lead to limited

physical dependence or psychological

dependence relative to the drugs or

other substances in schedule III.

+ Schedule V: (A) The drug or

other substance has a low potential for

abuse relative to the drugs or other

substances in schedule IV. (B) The drug

or other substance has a currently

accepted medical use in treatment in the

United States. (C) Abuse of the drug or

other substance may lead to limited

physical dependence or psychological

dependence relative to the drugs or

other substances in schedule IV.

Geographic region—The 50 states

and the District of Columbia are

grouped for statistical purposes by the

U.S. Census Bureau into the following

four geographic regions:

Region States included

Northeast Maine, New Hampshire,

Vermont, Massachusetts,

Rhode Island, Connecticut,

New York, New Jersey, and

Pennsylvania;

Midwest Ohio, Indiana, Illinois,

Michigan, Wisconsin,

Minnesota, Iowa, Missouri,

North Dakota, South Dakota,

Nebraska, and Kansas;

South Delaware, Maryland, District

of Columbia, Virginia, West

Virginia, North Carolina,

South Carolina, Georgia,

Florida, Kentucky, Alabama,

Mississippi, Arkansas,

Louisiana, Oklahoma, and

Texas;

West Montana, Idaho, Wyoming,

Colorado, New Mexico,

Arizona, Utah, Nevada,

Washington, Oregon,

California, Alaska, and

Hawaii.

Hospital —A hospital is eligible for

inclusion in NHAMCS if it has an

average length of stay for all patients of

less than 30 days (short-stay) or if it has

a specialty of general (medical or

surgical) or children’s general. The

survey excludes federal hospitals,

hospital units of institutions, and

hospitals with less than six beds staffed

for patient use.

Metropolitan status—Providers are

classified by their location in a

metropolitan statistical area or

nonmetropolitan statistical area as

follows:

+ Metropolitan statistical area

(MSA)—As defined by the U.S.

Office of Management and

Budget, the definition of an

individual MSA involves two

considerations: first, a city or

cities of specified population

that constitute the central city

and identify the county in which

it is located as the central

county; second, economic and

social relationships with

‘‘contiguous’’ counties that are

metropolitan in character so that

the periphery of the specific
Series 13, No. 163 [ Page 37

metropolitan area may be

determined. MSAs may cross

state lines. In New England,

MSAs consist of cities and

towns rather than counties.

+ Non-MSA—Non-MSA areas are

those not defined as MSAs.

Office—An office is the space

identified by a physician as a location

for his or her ambulatory practice.

Offices customarily include consultation,

examination, or treatment spaces that

patients associate with the particular

physician.

Office-based physician—A

physician is a duly licensed doctor of

medicine (M.D.) or doctor of osteopathy

(D.O.) who is currently in office-based

practice and who spends some time

caring for ambulatory patients. Excluded

from NAMCS are physicians who are

hospital based; who specialize in

anesthesiology, pathology, or radiology;

who are federally employed; who treat

only institutionalized patients; or who

are employed full time by an institution

and spend no time seeing ambulatory

patients.

Outpatient department (OPD)—An

OPD is a hospital facility where

nonurgent and ambulatory medical care

is provided under the supervision of a

physician.

Population rate—The population

rate is a basic measure of service

utilization for event-based surveys. In

this report, the numerator is the number

of occurrences of therapeutic classes of

drugs prescribed, provided, or continued

at ambulatory care visits and the

denominator is the corresponding U.S.

population estimate for those who could

have made the visits. The interpretation

is that for every person in the

population, there are x occurrences of

therapeutic classes of drugs prescribed,

provided, or continued at ambulatory

care visits. It does not mean that x

percentage of the population was

prescribed drugs of particular classes at

ambulatory care visits because some

persons in the population make no visits

while others make multiple visits within

a given year, and some persons make

visits at which no drugs are prescribed.

The population rate is best used to

compare amounts of utilization across

various subgroups of interest such as

age, race, or geographic region (e.g., the

rate of antihistamine drug classes for

drugs reported at U.S. ambulatory care

visits in 2003–04 was 339.2 per 1,000

females and 211.6 per 1,000 males).

Prescription status—Prescription

status refers to whether a drug is

available by prescription only or as an

over-the-counter (nonprescription)

preparation. Drugs that are available as

either prescription or over-the-counter

preparations (for example, ibuprofen)

are classed in an ‘‘undetermined’’

category in NAMCS and NHAMCS.

Primary expected source of

payment—The primary expected source

of payment is the source that, to the best

of the provider’s knowledge, describes

how charges incurred during this visit

will be paid.

+ Private insurance—This

category includes charges paid

in part or in full byaprivate

insurance company, health

maintenance organization

(HMO) plan, or other

prepayment plan, including

independent practice associations

(IPAs) and preferred provider

organizations (PPOs).

+ Medicare—This category

includes charges paid in part or

in full by a Medicare plan,

including payments made

directly to the hospital as well

as payments to the patient.

+ Medicaid/SCHIP—This category

includes charges paid in part or

in full by Medicaid or a State

Children’s Health Insurance Plan

(SCHIP), including payments

made directly to the hospital as

well as payments to the patient.

SCHIP, enacted as part of the

Balanced Budget Act of 1997,

gave states the opportunity to

provide free or low-cost

insurance coverage to

low-income children not

otherwise eligible to be covered

by Medicaid. States began

enrolling children in 1998 using

Medicaid or state-specific

programs separate from

Medicaid, or both. By 2000, all

states had implemented their

SCHIP programs.

+ Worker’s compensation—This

category includes programs

designed to enable employees

injured on the job to receive

financial compensation

regardless of fault.

+ Self-pay—This category includes

charges that are billed directly to

the patient and will not be

reimbursed by a third party.

Self-pay does not include

prepaid plans for which a

copayment is charged.

+ No charge—No fee is charged

for these visits. This category

does not include visits paid for

as part of a total care package

(e.g., postoperative visits

included in a surgical fee,

pregnancy visits for which a flat

fee was charged, and HMO and

prepaid systems).

+ Other—This category includes

other sources of payment not in

the preceding categories, including

charges paid under CHAMPUS,

state and local governments,

private charitable organizations,

and other liability insurance.

+ Unknown—This category

includes cases for which none of

the previous sources of payment

categories was checked.

For this report, visits were designated

‘‘uninsured’’ if either self-pay or no charge

was indicated. ‘‘Other’’ sources included

worker’s compensation, other, and

unknown.

Visit —For NAMCS, a visit is a

direct personal exchange between an

ambulatory patient and a physician or a

staff member working under the

physician’s supervision for the purpose of

seeking care and rendering personal health

services. The NAMCS sample excludes

visits where medical care was not

provided (e.g., visits made to drop off

specimens, pay bills, make appointments,

and walkouts). For NHAMCS, a visit is a

direct, personal exchange between a

patient and a physician or other health

care provider working under the

physician’s supervision for the purpose of

seeking care and receiving personal health

services.
Page 38 [ Series 13, No. 163

Appendix III

Survey Instruments
Series 13, No. 163 [ Page 39
Page 40 [ Series 13, No. 163
Vital and Health Statistics

series descriptions

SERIES 1. Programs and Collection Procedures—These reports

describe the data collection programs of the National Center

for Health Statistics. They include descriptions of the methods

used to collect and process the data, definitions, and other

material necessary for understanding the data.

SERIES 2. Data Evaluation and Methods Research—These reports

are studies of new statistical methods and include analytical

techniques, objective evaluations of reliability of collected

data, and contributions to statistical theory. These studies

also include experimental tests of new survey methods and

comparisons of U.S. methodology with those of other

countries.

SERIES 3. Analytical and Epidemiological Studies—These reports

present analytical or interpretive studies based on vital and

health statistics. These reports carry the analyses further than

the expository types of reports in the other series.

SERIES 4. Documents and Committee Reports—These are final

reports of major committees concerned with vital and health

statistics and documents such as recommended model vital

registration laws and revised birth and death certificates.

SERIES 5. International Vital and Health Statistics Reports—These

reports are analytical or descriptive reports that compare U.S.

vital and health statistics with those of other countries or

present other international data of relevance to the health

statistics system of the United States.

SERIES 6. Cognition and Survey Measurement—These reports are

from the National Laboratory for Collaborative Research in

Cognition and Survey Measurement. They use methods of

cognitive science to design, evaluate, and test survey

instruments.

SERIES 10. Data From the National Health Interview Survey—These

reports contain statistics on illness; unintentional injuries;

disability; use of hospital, medical, and other health services;

and a wide range of special current health topics covering

many aspects of health behaviors, health status, and health

care utilization. They are based on data collected in a

continuing national household interview survey.

SERIES 11. Data From the National Health Examination Survey, the

National Health and Nutrition Examination Surveys, and

the Hispanic Health and Nutrition Examination Survey—

Data from direct examination, testing, and measurement on

representative samples of the civilian noninstitutionalized

population provide the basis for (1) medically defined total

prevalence of specific diseases or conditions in the United

States and the distributions of the population with respect to

physical, physiological, and psychological characteristics, and

(2) analyses of trends and relationships among various

measurements and between survey periods.

SERIES 12. Data From the Institutionalized Population Surveys—

Discontinued in 1975. Reports from these surveys are

included in Series 13.

SERIES 13. Data From the National Health Care Survey—These

reports contain statistics on health resources and the public’s

use of health care resources including ambulatory, hospital,

and long-term care services based on data collected directly

from health care providers and provider records.

SERIES 14. Data on Health Resources: Manpower and Facilities—

Discontinued in 1990. Reports on the numbers, geographic

distribution, and characteristics of health resources are now

included in Series 13.

SERIES 15. Data From Special Surveys—These reports contain

statistics on health and health-related topics collected in

special surveys that are not part of the continuing data

systems of the National Center for Health Statistics.

SERIES 16. Compilations of Advance Data From Vital and Health

Statistics—Advance Data Reports provide early release of

information from the National Center for Health Statistics’

health and demographic surveys. They are compiled in the

order in which they are published. Some of these releases

may be followed by detailed reports in Series 10–13.

SERIES 20. Data on Mortality—These reports contain statistics on

mortality that are not included in regular, annual, or monthly

reports. Special analyses by cause of death, age, other

demographic variables, and geographic and trend analyses

are included.

SERIES 21. Data on Natality, Marriage, and Divorce—These reports

contain statistics on natality, marriage, and divorce that are

not included in regular, annual, or monthly reports. Special

analyses by health and demographic variables and

geographic and trend analyses are included.

SERIES 22. Data From the National Mortality and Natality Surveys—

Discontinued in 1975. Reports from these sample surveys,

based on vital records, are now published in Series 20 or 21.

SERIES 23. Data From the National Survey of Family Growth—These

reports contain statistics on factors that affect birth rates,

including contraception, infertility, cohabitation, marriage,

divorce, and remarriage; adoption; use of medical care for

family planning and infertility; and related maternal and infant

health topics. These statistics are based on national surveys

of women of childbearing age.

SERIES 24. Compilations of Data on Natality, Mortality, Marriage, and

Divorce—These include advance reports of births, deaths,

marriages, and divorces based on final data from the National

Vital Statistics System that were published as National Vital

Statistics Reports (NVSR), formerly Monthly Vital Statistics

Report. These reports provide highlights and summaries of

detailed data subsequently published in Vital Statistics of the

United States. Other special reports published here provide

selected findings based on final data from the National Vital

Statistics System and may be followed by detailed reports in

Series 20 or 21.

For answers to questions about this report or for a list of reports published

in these series, contact:

Information Dissemination Staff

National Center for Health Statistics

Centers for Disease Control and Prevention

3311 Toledo Road, Room 5412

Hyattsville, MD 20782

1-866-441-6247

E-mail: nchsquery@cdc.gov

Internet: www.cdc.gov/nchs
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DHHS Publication No. (PHS) 2007-1734, Series 13, No. 163