t 

FROM VITAL & HEALTH STATISTICS OF THE NATIONAL CENTER FOR HEALTH STATISTICS 

U.S. DEPARTMENT OF HEALTH, EDUCATION, AND WELFARE � Public Health Service I Number 30 � July 13,1978 

1976 Summary:


National Ambulatory Medical Care Survey’


The estimates in this report highlight the 

findings of the 1976 National Ambulatory MedicaI Care Survey (NAMCS), a sample survey 

designed to explore the provision and utilization 

� of ambulatory care in the physician’s office—the 

setting where most Americans seek health care. 

The survey is conducted yearly in the coterminous United States by the Division of Health 

Resources Utilization Statistics. The survey 

sample is selected from doctors of medicine and 

osteopathy who are principally engaged in 

office-based, patient-care practice. In its current 

scope, NAMCS excludes physicians practicing in 

Alaska and Hawaii; physicians whose specialty is 

anesthesiology, pathology, or radiology; physicians in Federal service. 

Figure 1 is a facsimile of the Patient Record 

used by participating physicians to record information about their office visits in both the 1975 

and 1976 survey years. The reader may find it 

useful to refer to figure 1 as selected aspects of 

the survey findings are presented. 

Since the estimates presented in this report 

are based on a sample rather than the entire universe of office-based, patient-care physicians, 

they are subject to sampling variability. See 

“Technical Notes” at the end of this report for 

an explanation and for guidelines in judging the 

relative precision of the estimates presented. 

, 1This report was prepared by Hugo Koch, Raymond 

O. Gagnon, and Trena Ezzati, Division of Health Resources Utilization Statistics. 

DATA HIGHLIGHTS 

Physician Characteristics 

Among the 12 most visited specialists, primary care providers led the other specialists in 

the provision of office-based, ambulatory care; 

two of these providers, general/family physicians 

and internists, accounted for one-half of all 

visits. In a ratio of about 3 to 2, visits to solo 

practitioners clearly outnumbered visits to 

physicians in multiple-member practice. (See 

table 1.) 

Patient Characteristics 

Number of office visits per person per year 

generally increased in a direct parallel to advancing age; the rate for persons aged 65 years and 

over was more than double the rate for persons 

under 15 years. Females reported more visits to 

the physician’s office than males did; for every 2 

visits made by miles, there were about 3 visits 

by females. This 2-to-3 ratio also prevailed for 

annuaI visit rates between the sexes. The data in 

table 2 reveal that visits by females outnumbered visits by males in every age interval 

above 14 years of age. 

Clinical Characteristics 

Reason for visit.-The information in item 5 

of the Patient Record represents the reasons for 

visiting the physician’s office as expressed by 
2 tldwlncedata 

patients in their own words. The terms and 

codes applied to the patient’s symptoms, complaints, or other problems come from a symptom classification developed for use in 

NAMCS.Z Table 3 confines itself to “symptomatic” reasons for the visit, listing in rank. order 

the 25 complaints or symptoms most frequently 

presented. “Nonsymptomatic” reasons such 

as physical examinations and visits for medication are excluded from the tabulation. 

Principal diagnosis. –Table 4 lists the 25 

most common principal diagnoses that were provisionaHy or finally assigned to office visits by 

the physician. Table 5 shows the classification of 

all principal diagnoses by the major diagnostic 

groups. The diagnostic terms and codes are those 

established in the Eighth Revision International 

Classification of Diseases, Adapted for Use in the 

United States, 1968 (ICDA). The considerable 

effort that office-based physicians devote to 

preventive and maintenance care–as opposed to 

care that is primarily morbidity related—is evident in the finding that 18 percent of visits 

center on examinations without illness and on 

such special conditions as immunizations, prenatal and postnatal care, and medical and surgical aftercare (table 5). 

Diagnostic and therapeutic services. —The 

limited examination was the diagnostic tool 

most frequently used in office-based practice; 

drug therapy was the most frequent form of 

treatment. The finding that blood pressure was 

taken in about one-third of visits may cast some 

doubt on the general employment of this proc e dur e as a routine detection mechanism. 

“Counseling” was checked by the physician only 

when it constituted a major part of the treatment provided during the visit. The overall use 

of such an intangible service is almost impossible 

to quantify. CertainIy, the finding that counseling was prominent in only 14 percent of visits 

understates the actual. extent of this important 

aspect of the pliysician’s office practice. 

2 National Center for Health Statistics: The National 

Ambulatory Medical Care Survey: Symptom Classification, United States. Vital and Health Statistics. Series 

2-No. 63. DHEW Pub. No. (HRA) 74-1337. Health 

Resources Administration. Washington. U.S. Government Printing Office, May 1974. 

Other Visit Characteristics 

Data about prior-visit status (table 7) reveal 

that the average office-based physician dealt 

chiefly with patients that he had seen before 

(“old” patients). New patients accounted for 

only 1 of every 7 visits. Furthermore, the physician dealt chiefly with probIems for which he 

previously had treated the patient (“old” problems). Only about 1 of every 4 visits by an old 

patient concerned a new probIem. New problem 

encounters (i.e., any problem presented by a 

new patient or a new problem presented by an 

old patient) accounted for about 37 percent of 

all visits. The remaining visits (i.e., old problems 

presented by old patients) offer a rough estimate 

of the average number of return visits made during the year for any given new problem. Thus, 

for a typical new problem presented in 1976, 

there was an average of 1.7 return visits in the 

course of that year. 

Data on seriousness (table 7) express the 

physician’s judgment as to the extent of impairment that might result if no care were avaiIable � 

for the given problem. Office-based ambulatory 

care does not center on the treatment of problems that bear a “serious and very serious” 

prognosis. Only about 1 of every 5 visits belonged in this category. The largest proportion 

-of visits (an estimated 48 percent) was given a . 

“not serious” evaluation. This is due in large 

degree to the substantial amount of preventive 

care and routine maintenance care provided in 

the physician’s office, and to the relatively high 

prevalence of acute, self-limiting conditions encountered there. 

Some form of scheduled followup was the 

rule in office-based practice (see findings on disposition, table 7). In about 61 percent of visits “ 

the patient was directed to return at a specified 

time. OnIy 2 percent of visits resulted in hospital 

admission, a finding that reflects the nonserious 

character of most” visits made to office-based 

physicians. 

Duration of visits (table 7) is based on the estimated time spent in face-to-face encounter between patient and physician. The average encounter lasted about 15 minutes. Visits of O-minute 

duration are those where there was no contact 

between physician and patient. These chiefly in- ? 

volved visits during which the patient was provided care by a member of the physician’s staff. 
---

� 

ackmeaa3 

Figure 1. PATlENT RECORD 

ASSURANCE OF CONFIDENTIAL IT’: All ?:,.rnut,or, /Jk,ch w,>.ad ~,,- ! d.nldlc.tmn of m mdwadwl.


a .mctxce. or n. csmhlnshmcnt u+ ho Mu cc.Itdrmt 3!. v. ,!1(w ..+ only b. ~ets!ms engaged in md f.r C532201
 !:.. ~,.tpsps dThe s.r.q
 ,md wll nor P,. c :dw..d c,, r,:l..wd 1. t Ih,.r ;$!!-%>.s a used la my other purpose. 

? . DATE OF VISIT PATl ENT RECORD 

&,y,T NAT!ONAL AMBULATORY MEDICAL CARE SURVEY 

2.	 9ATE OF BIRTH ~. COLOR OR 5. ?ATIENT’S PRINCIPAL PROBLEM(S) 6. SERIOUSNESS OF 7. iiA’JE YOU EVER SEEN 

RACE COMPLAINT(S), OR SYMPTOM(S) w VISIT PROBLEM IN ITEM 5a THIS PATIENT BEFORE? 

, ~ ~HITE (/._sww7wmfsj (Check one) ,. . ~ YES 2UN0 

3. SEX BLACK IMPORT4NT ? Z SERfOUS If YES, for the problem 

indicated in ITEM 5a? : FEMALE , Z OTHER , g SLIGHTLY SERIOUS 

.“ n MALE . r UNKNOWN b C)Th:R . z NOT SERIOUS ~ 5 YES 21JN0 

2 ~: NEGROf .3 MOST I n VERY SERIOUS i 

& MAJOR REGSON(S) FOR THIS	 VISIT (Ckci d/mvor femml 9. PHYSICIAN’S PRINCIPAL DIAGNOSIS~ VISIT — 

a. OIAGNOSIS ASSOCIATE WITH ITEM 5a ENTRY 

~ ACUTE PROBLEM [ V.IEL: AOLILT, CHILG EXAM 

~ ACUTE PRCBLEM. FOLLOW-UP , ~ FfirL:lLY PLANNING 

. c CHRONIC PROBLEM, ROUTINE z COUNSE: !:JG ADVICE 

C CHRONIC ‘R OELEM, FLARE-L!? lMMUNtZAilON 

I z PRENATAL CARE u REFE?REC BY OTMFR PHYS!AGENCY b. OTHER SIGNIFICANT CURRENT OIAGNosES 

* U POSTNATAL CARE :: #o~,f,J,sTR*T,lJ~ pu~pos~ (In order of importance) 

z POSTOPERATIVE CARE ‘_ OTHER (SPWA,) 

-+ 

—.— 

(Dperatwe procedure) 

10. DIAGMOSTIC,THERAPEUTIC SERVICES OROERED/PROVIOEiE THIS VISIT (CfMcka//Zhar W/Y) 11. DISPOSITION THIS VISIT 12. DURATION OF 

01 � NONE II O ORUG PRESCRISEO {Chockair that ~) ~ VISIT [T/imI 

actually spent with 

02 � LIMITEO HISTORYIEXAM :2 � X. RAY physician) 

03 � GENERAL HISTORYIEXAM 13 D INJECTION I n NO COLLOW.UP PLANNEO 

04 D CLINICAL LAB. TEST 14 D IMMUN[ZAT[ONIOESENSITIZATIOV 1 � RETURN AT SPECIFIED TIME 

05 D BLOOO PRESSURE CHECK 15 0 PHYSIOTHERAPY I ~ RETURN IF NEEOEO, PRN 

06 � EKG 16 � MEOICAL COUNSELING . � TELEPHONE FOLLOW-UP PLANNEO 

07 0 HEARING TEST 17 � PSYCHOTHERAPYITHERAPEUTIC 5 0 REFERREO TO OTHER -.—MINUTES 

08 D VISION TEST LISTENING PHYSICIAN/AGENCY 

09 � ENOOSCOPY 18 � OTHER l.%~”fy) t � RETURNEO TO REFERRING 

PHYSICIAN 

10 � OFFICE SURGERY I � AOMIT TO HOSPITAL 

e D OTHER (Speedy) 

ZA-34-4 DEPARTMENT OF HEALTH, EDUCATION AND WELFARE O.M.B. #S8-S72106 

w. 8-7s PUBLIC HEALTH SERVICE 

I+ EALTH RSSOURCES ADMINISTRATION 

NATIONAL CENTER FOR HEALTH STATISTICS 
4


Table 1. Number and percent distribution of office visits and mean number of office visits per week, by selected phvsician characteristics: United States, January-December 1976 

Number Mean 

of visits Percent number of 

Physician characteristic 

in distribution office visits 

thousands per weekl 

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

Specialty 

General and family practice ... .................................. 

Internal medicine ........ .................. .......................... 

Pediatrics .................... ............ ................ ................. 

Obstetrics and gynecology ....................................... 

General surgery .. ......... .................. .......................... 

Ophthalmology .. ..................................................... 

Orthopedic surgery ......................... ......................... 

Dermatology ............... .......... ...... ............................ 

Psychiatry ................. .. .................. .... ...................... 

Otolaryngology ......... .............................................. 

Urology ... ................... ........ ..................................... 

Cardiovascular disease ............................................. 

All other specialties ... ...... .................... .................... 

Type of practice 

solo4................o....................................................... 0ther2 ............................... .............. ........................ 

588,300 100.0 78 

225,637 38.4 111 

68,249 11.6 62 

60,400 10.3 113 

48,994 8.3 74 

35,967 6.1 46 

29,302 5.0 86 

27,837 4.7 64 

21,627 3.7 140 

15,811 2.7 29 

10,837 1.8 77 

9,896 1.7 53 

5,961 1.0 39 

27,782 4.7 

353,854 60.2 78 

234,446 39,8 77 

lAPPlies only to sampled Physicians who actively treated patients during the week Of their Participation. 

21nc]udes partnership and grouP Practice. 
o 

acklncedata 5 

Table 2. Number and percent distribution of office 

United 

Age and sex of patient 

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

Age

. 

Under 15 years .............. ..................................... .... . 

15-24 years .......................... ... ................... .............. 

2544 years ........................................ ...................... 

45-64 years .............. ............ ........ ............... ............. 

65 years and over ..... ...... ............ ....................... ...... 

Sex and age 

Female ........ ....................................... ......... ........ 

Under 15 years ........................................ ..... ........... 

15-24 years .. ................ ................... ......................... 

25-44 years ... .............. ...... ...... ................ ....... .......... 

45-64 years ... .......................................... ............ ..... � 65 years and over ....................................................

Male .................... ......................................... ....... 

Under 15 years ...................... ...... ............................ 

15-24 years ............ ........ ...... ... ................................. 

2544 years .......................... ........ ...... ...................... 

45-64 years ....................................................... ....... 

65 years and over .................................................... 

visits and number of visits per person per year, by patient’s age and sex: 

States, January-December 1976 

Number Number 

of visits Percent of visits 

in distribution per person 

thousands per year 

588,300 100.0 2.8 

109,995 18.7 2.1 

88,403 15.0 2.3 

151,107 25.7 2.8 

144,708 24.6 3.4 

94,087 16.0 4.3 

354,831 60.3 3.3 

52,240 8.9 2.0 

57,766 9.8 2.9 

99,367 16.9 3.6 

86,794 14.8 3.9 

58,661 10.0 4.6 

233,470 39.7 2.3 

57,756 9.8 2.2 

30,635 5.2 1.6 

51,740 8.8 2.0 

57,913 9.8 2.8 

35,426 6.0 4.0 

NOTE: Rates are based onthecivilian noninstitutionalized population, excluting Maskaand Ha\\faii. 
---

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

6 admncedata 

..- . ..> 

Table 3. Number and percent of office visits, by most common complaints or symptoms classified by NAMCS codein rank order: 

United States, January-December 1976 .._—— 

Number 

Most common symptom or complaint of visits Percent 

Rank expressed by patient of 

in 

and NAM CS code visits 

thousands 

Pain, swelling, injury–lower extremity ..............4OO 

Pain, swelling, injury–back region .....................4l 5 

Sore throat .............................. ..........................52O 

Pain, swelling, injury–upper extremity .............405 

Abdominal pain .................................................54O 

Cough ...... ..........................................................3ll 

Cold ......................................... .........................3l 2 

Allergic skin reactions ..... ..................................1 12 

Headache ...........................................................O56 

Pain in chest ................................ ......................322 

Fatigue ............ ................ ..................................OO4 

Pain, swelling, injury–face and neck ,...............,410 

Vision dysfunction, except blindness ................701 

Fever .......................................................... .......OO2 

Wounds of skin ...... ............................................l 16 

Abnormally high blood pressure ........................2O5 

Earache .................. ...........................................735 

Weight gain .. ......................................................Ol O 

Vertigo ........ .............. ........................................O69 

Nasal congestion ................................................3ol 

Acne or pimples ................................................l OO 

Swelling or mass of skin ....................................1 15 

Shortness of breath ..................... ......................306 

Depression .........................................................8O7 

Vaginal discharge ... ............................................662 

21,178 

16,932 

16,168 

15,902 

14,590 

13,099 

10,844 

10,679 

9,908 

9,564 

9,468 

9,122 

8,569 

8,535 

8,492 

7,518 

7,487 

6,956 

6,703 

6,488 

6,310 

5,855 

5,843 

4,377 

4,377 

—	 3.6 

2.9 

2.8 

2.7 

2.5 

2.2 

1.8 

1.8 

1.7 

1.6 

1.6 

1.6 

1.5 

1.5 

1.4 

1.3 

1.3 

1.2 

1.1 

1.1 � 

1.1


1.0 

1.0 

0.7 

0.7 
1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

achme&b7 

Table 4. Number and percent of office visits, by most common principal diagnoses classified by ICDA code in rank order: United States, 

Rank 

� 19 

20 

21 

22 

23 

24 

25 

Jar 

Most common principal diagnosis 

and ICDA code 

Medical or special examination ............. ............YOO 

Medical and surgical examination .....................YI O 

Essential benign hypertension .. ..................... ....401 

Prenatal care ......................... ............................ Y(I6 

Acute upper respiratory infection .....................465 

Chronic ischemic heart disease .... ......................41 2 

Neuroses ............................................................3oo 

Otitis media .......................................... .............38l 

Other eczema and dermatitis .............................692 

Diabetes mellitus .................... ...........................25O 

Hay fever ........................ ..................................5o7 

Refractive errors ................................................37O 

Acute pharyngitis ................................... ..... ......462 

Diseases of sebaceous gland ..... ..........................706 

Obesity ..... .................................................... .....277 

Bronchitis, unqualified ......................................490 

Osteoarthritis and allied conditions ...................71 3 

Sprains and strains of other and 

unspecified parts of back .................................847 

Asthma ............. ............ ........ .............................493 

Acute tonsillitis ..................... ............................463 

Synovitis, bursitis, tenosynovitis .......................731 

Other viral diseases .. ................................... .......o79 

Diarrheal diseases ............. ...... ...........................OO9 

Arthritis, unqualified .................................. .......7l 5 

Observation, without need for 

further medical care ...... ..................................793 

ry-December 1976 / 

Number 

Percent of visits 

of in 

visits thousands 

44,736 7.6 

29,598 5.0 

23,303 4.0 

21.425 3.6 

18;641 3.2 

13,507 2,3 

12,058 2.1 

10,715 1.8 

9,744 1.7 

9,605 1.6 

9,337 1.6 

9,052 1.5 

8,883 1.5 

8,719 1.5 

8,288 1.4 

7,248 1.2 

7,012 1.2 

6,520 1.1 

6,319 1.1 

6,168 1.1 

5,661 1.0 

5,659 1.0 

5,448 0.9 

4,781 0.8 

4,353 0.7 
.0 

8 acmlncedata 

Table 5. Number and percent distribution of office visits, by principal diagnosis classified by major iCDA group: United States, 

January-December 1976 

Principal diagnosis classified by major 

diagnostic group and I CDA code 

All principal diagnoses ....................................... 

Infective and parasitic diseases ........ ...........000-1 36 

Neoplasms ................. ............ .. ...................l4O.239 

Endocrine, nutritional, and 

matabolic diseases ., ..................................240-279 

Mental disorders .........................................290-31 5 

Diseases of the nervous system 

and sense organs .......................................32O.389 

Diseases of the circulatory system ... ...........390-458 

Diseases of the respiratory system ..............460.51 9 

Diseases of the digastive system ..................520-577 

Diseases of the genitourinary system ..........580-629 

Diseases of the skin and 

subcutaneous tissue ..................................68 O-7O9 

Diseases of the musculoskeletal 

system ...................... ................................71 O.738 

Symptoms and ill-defined conditions .........780-796 

Accidents, poisoning:, and violence ............8OO-999 

Special conditions and examinations 

without sickness ....................... .. ............ YOO-Y13 

Residual ................................. ...... ........................... 

1 I 

Number 

of visits Percent 

in distribution 

thousands 

{ 1 

588,300 I 100.0 

I 

25,327 4.3 

12,346 2.1 

24,724 4.2 

23,446 4.0 

49,220 8.4 

54,259 9.2 

83,276 14.2 

18,235 3.1 

34,143 5.8 

33,088 5.6 

33,151 5.6 

27,549 4.7 

43,985 7.5 � 

108,578 18.5 

16,973 2.9 
dmcdata9 

Table 6. Number and percent of office visits, by diagnostic and 

therapeutic services provided: United States, JanuaryDecernber 1976 

Diagnostic and therapeutic 

services provided 

(selected procedures) 

Diagnostic services 

Limited history or examination ...... ... 

General history or examination .. ........ 

Clinical lab test .. ................................ 

X.ray ................ ................ .................. 

Blood pressure check ........ ................. 

EKG ...... ........... ........ ........ .................. 

Hearing test.., ..................................... 

Vision test ..................................... ..... 

Endoscopy .................................. ....... 

Therapeutic services 

Drug prescribed .................................. 

Injection ............................................ 

Immunization or desensitization ........ 

Off ice surgery ............................ ........ �Physiotherapy ....................................

Medical counseling ........... .................. 

Psychotherapy and therapeutic 

listening ........................................... 

Number 

Percent of visits 

of in 

visits :housands 

305,231 51.9 

99,309 16.9 

133,598 22.7 

45,527 7.7 

195,179 33.2 

19,370 3.3 

7,873 1.3 

30,684 5.2 

6,809 1.2 

251,970 42.8 

73,309 12.5 

31,287 5.3 

41,497 7.1 

17,590 3.0 

79,920 13.6 

24,249 4.1 

Table 7. Number and percent distribution of office visits, by 

selected visit characteristics: United States, January-December 

1976 

I Number 

of visits Percent 

Selected visit characteristic I in Distribution 

I thousands 

All visits ..................................... .. I 

t 

Prior-visit status I 

New patient ................................ ....... 

Old patient, new problem .................. 

Old patient, old problem .................. .. 

Seriousness of problem I 

Serious and very serious ..... .... ............ 

Slightly serious, .. .............. ............... ... 

Not serious .................. ....................... 

Disposition] I No +OI!OWU13 . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . 

Return at specified time ..... ................ 

Return if needed ................................ 

Telephone followup ........ ................... 

Referred to other physician 

or agency .................... .............. ....... 

Returned to referring physician .. ....... 

Admit to hospital ....... ........................ 

Duration of visit 

I 

O minute (no face-to-face 

encounter with physician) ................ 

1-5 minutes ........................................ 

6-10 minutes ............................... ...----

11-15 minutes .....s....s......................... 

16-30 minutes ....... .. ........................... 

31 minutes or more ............................ 

588,300 100.0 

83,606 14.2 

135,107 23.0 

369,587 62.8 

114,909 19.5 

189,886 32.3 

283,506 48.2 

67,599 11.5 

361,149 61.4 

126,283 21.5 

19,142 3.3 

16,281 2.8 

4,800 0.8 

12,222 2.1 

13,560 2.3 

83,106 14.1 

186,802 31.8 

154,994 26.4 

117,894 20.0 

31,943 5.4 

l}WIU not add to totals since more than one disposition was 

possible. 
10 achancedata 

TECHNICAL NOTES 

SOURCE OF DATA: Data presented in this Table 1. Approximate relative standard errors of estimated numreport were obtained during 1976 through the Na- bers of office visits 

tionaI Ambulatory Me dicaI Care Survey I Relative 

compasses office visits within the coterminous Estimate in thousands percentages 

United States made to physicians who are princi- points 

pally engaged in office practice. 5oo . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . 30.1 

SAMPLE DESIGN: The 1976 NAMCS utilized a 1.ooo ....................................................... 21.4 

multi stage probability design that involved 2.000 . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

5.000 . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

15.3 

10.0 

samples of primary sampling units (PSU’5), lo.ooo . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.5 

physician practices within PSU’S, and patient 30.000 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . 5.1 

(NAMCS). The target population of NAMCS en- standard error in 

visits within practices. Within the 87 PSU’S com- loo.ooo .. . ... ... .. ... ... . .. .. .. .... . .... . .. .... ... . .... .. . 4.0 

550.000 ... .... ..... . . .... .. . .... .. .. .. .... .. .... .. .. ..... . 3.5 

posing the first stage of selection, a sample of 

approximately 3,000 physicians was selected Example of use of table: An aggregate of 80,000,000 has a 

relative standard error of 4,3 percent or a standard error of 

from master files maintained by the American 3,440,000 (4.3 percent of 80,000,000). 

Medical Association and the American Oste­


opathic Association. Sampled physicians, ran- Table II. Approximate standard errors of percents for estimated


domly assigned to 1 of the 52 weeks in the sur- numbers of office visits


vey year, were requested to complete Patient 

Estimated percent �


Records (figure 1) for a systematic random Base of percent


sample of office visits taking place within their (number of visits 1 or 5 or 10or 20 or 30 or so 

practice during the assigned reporting period. in thousands) 99 95 90 80 70


Additional data concerning physician practice


characteristics such as primary specialty and Standard error in percentage points


type of practice were obtained during an in- 1,000 ..................... 2.1 4.6 6.3 8.5 9.7 10.6 

duction interview. 3,000 ..... . .. .... . .. . .... . 1.2 2.7 3.7 4.9 5.6 6.1 

A complete description of the survey’s back- 5,000 .. ... ... . .... ... ..... 0.9 2.1 2.8 3.8 4.3 4.7 

10,000 .. .... .. . ... ... ... . 0.7 1.5 2.0 2.7 3.1 3.3 ground and development has been pubIished in 50,000 .. .. ... .. ... .. .. . .. 0.3 0.7 0.9 1.2 1.4 1.5 

Series 2, No. 61, of Vital and Health Statistics, 100,000 ...... . .. ... .. ... 0.2 0.5 0.6 0.8 1.0 1.1 

DHEW Pub. No. (HRA) 76-1335, Health Re- 500,000 .. ..... ... .... ... 0.1 u0.2 0.3 0.4 0.4 0.5

sources Administration, Washington, U.S. Gov- Examule of use of table: An estimate of 30 wrcent based on 

ernment Printing Office, Apr. 1974. an aggregate o; 75,060,000 has a standard error of 1.2 percent. 

The relative standard error of 30 percent is 4.0 percent (1.2 SAMPLING ERRORS: Since the estimates for percent+30 percent). 

this report are based on a sample rather than the 

entire universe, they are subject to sampling variability. The standard error is primarily a measure unrounded figures. Due to rounding of percents, 

of sampling variability. The relative standard the sum of percentages may not equal 100.0. 

error of an estimate is obtained by dividing the DEFINITIONS: An ambulatory patient is an instandard error of the estimate by the estimate dividual presenting himself for personal health 

itself and is expressed as a percent of the esti- services who is neither bedridden nor currently 

mate. Relative standard errors of selected aggre- admitted to any health care institution on the 

gate statistics are shown in table I. The standard premises. 

errors appropriate for the estimated percent of An o~~ice is a place that the physician idenoffice visits are shown in tabIe II. tifies as a location for his ambulatory practice. 

ROUNDING: Aggregate estimates of office visits Responsibility over time for patient care and 9 

presented in the tables are rounded to the professional services rendered there generally 

nearest thousand. The rates and percents, how- resides with the individual physician rather than 

ever, were calculated on the basis of original, an institution. 
---

adwwdaa 11 

A visit is a direct personal exchange between 

an ambulatory patient and a physician or a staff 

member workhg under the physician’s supervision for the purpose of seeking care and 

rendering health services. 

A physician is a duly licensed doctor of 

medicine (M. D.) or doctor of osteopathy (D. O.) 

currently in practice who spends time in caring 

for ambulatory patients at an office location. 

Excluded from NAMCS are physicians practicing 

in Alaska and Hawaii; physicians who specialize 

in anesthesiology, pathology, or radiology; 

physicians who are federally empIoyed; physicians who treat only institutionaIized patients; 

physicians employed full time by an institution; 

and physicians who spend no time seeing ambulatory patients. 

SYMBOLS 

Data not avaiIable———.-———--—-——-—-—-

Category not applicable—--—-–-–—-—––––– 

Quantity zero-—-——-----–-——-

Quantity more than Obut less than 0.05— 

Figure does not meet standards of 

reliability or precision 

. . . 

-

0.0 

* 

GPO 931 397 
12 aciwncedata 

Recent Issues of Advance Data From Vital and Health Statistics 

No. 29.	 A Comparison of Nursing Home Residents and No. 27. Health Characteristics of Minority Groups, 

Dkchrrrges from the 1977 National Nursing United States, 1976 (Issued: Aprif 14, 1978) 

Home Survey: United States (Issued: May 17, 

1978) No. 26.	 Contraceptive Efficacy Among Married Women 15-44 Years of Age in the United States, 

1970-73 (Issued: April 6, 1978) 

No. 28.	 Office Visits for Hypertension: National Ambulatory Medicrd Care Survey, United States, No. 25. Office Y%its to Doctors of Osteopathy: Na­

~8n;arr8} 975-December 1976 (Issued: April t i o n al Ambulatory Medical Care Survey, 

, United States, 1975 (Issued: March 22, 1978) 

A complete list of Advance Data From Vital and Health Statsktics is available from the Scientific and Technical 

Information Branch. 

NCHS 

U.S. DEPARTMENT OF HEALTH, EOUCATION, AND WELFARE ‘POSTAGE AND FEES PAID Public Heslth Service * Nationsl Centsr for Health Statistics U.S. DEPARTMENT OF H.E.W. —“ 37COEasr.WestHighwaV US.MAIL 

Hyatewille, Maryland 20782 HEW-396 

c 

OFFICIAL BUSINESS


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