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

U.S. DEPARTMENT OF HEALTH, EDUCATION, AND WELFARE � Public Health Service I N“n-lber41 .
 October 30,1978 

Office Visits for Respiratory Conditions, National Ambulatory 

Medical Care Survey: United States, 1975-76’ 

According to data collected in the National 

Ambulatory Medical Care Survey (NAMCS) by 

the Nat ion al Center for Health Statistics 

(NCHS), an estimated 163.4 million visits to 

office-based physicians were attributed to diseases of the respiratory system during the 2-year 

period January 1975 through December 1976. 

Respiratory diseases comprised approximately 

14 percent of all office visits for that period and 

were the leading morbidity related ICDA2 classified group of diseases treated. 

NAMCS is a sample suvrey conducted annuaIly by NCHS’S Division of Health Resources 

Utilization Statistics. The estimates in this 

report are based on information recorded by 

part icipating physicians on brief encounter 

forms (see Technical Notes) during sampled 

office visits. A brief description of the sample 

design and an explanation of the sampling errors 

associated with selected aggregate statistics may 

be found in the Technical Notes of this report. 

Patients visiting with respiratory system 

complaints were likely to present new rather 

than continuing problems. This finding departs 

significantly from the general trend towards 

higher proportions of continuing problems in 

most morbidity related diagnostic groups. Figure 

1 illustrates the difference in problem status 

1“fhis report was prepared by BeuM K. CYPress, 

between visits for respiratory diseases and the 

total of all other ICDA diagnostic groups. 

Seriousness of the patient’s problem was 

evaluated by the physician using the criterion of 

the extent of impairment that might result if no 

care were available. On a 4-point scale ranging 

from not serious to very serious, attending 

physicians usually judged respiratory conditions 

as not serious or slightIy serious. A small proportion (14 percent) of these conditions was 

Tgure 1. PERCENT DISTRIBUTION OF OFFICE VISITS FOR DISEASES 

OF THE RESPIRATORY SYSTEM AND ALL OTHER MAJOR ICDA 

DIAGNOSTIC GROUPS, BY SERIOUSNESS AND PROBLEM 

STATUS UNITED STATES, 1975-76 

SERIOUSNESS PROBLEM STATUS 

Not serious m New problem E2z4 

Slightly serious Gmtinuing problem = 

Serious or very serious -

Iw 

80 

z 

0


F


~ 60


E 

~ 

E 

g 

~ 40


K


k!


Ph.D., Division of Health Resources Utilization Statistics. 

2National Center for Health Statistics: Eighth Revkion International Classification of Diseases, Adapted 

for Use in the United States. PHS Pub. No. 1693, Public Oiseases of the AU other f COA oiseases of the All other ICDA 

20 

rapiratory diagnostic respirator diagnostic Health Service. Washington. U.S. Government Printing system groups system groups 

Office, 1967. 
* 

2 &ncedata 

considered serious or very serious, which was 

less than the proportion (20 percent) of serious 

or very serious problems in the total of all other 

diagnostic groups (figure 1). 

Acute upper respiratory infections (acute 

URI), which are usually short duration, selflimiting conditions, accounted for almost half of 

the visits in the respiratory diseases group (table 

1). This may be one explanation for the relatively small proportion of office visits for 

serious problems. The high proportion of acute 

URI would also account for the relatively large 

numbers of new problems that were presented. 

Table 1. Number and percent distribution of office visits for 

acute and chronic diseases of the respiratory system: United 

States, 1975-76 

Number Percent 

Diagnosis and ICDA codel of visits in distribution 

thousands 

All visits .............460-519 163,401 100.0 

Acute upper respiratory 

infections .............. 460-466 78,585 48.1 

Acute nasopharyngitis and 

acute upper respiratory 

infections of multiple or 

unspecified sites .. . .... ...460.465 37,693 23.1 

Acute sinusitis . .. ... ..... .. .. .... .. 461 2,598 1.6 

Acute pharyngitis . . .... . . ..... .. . 462 17,414 10.7 

Acute tonsil litis .. ....... . ... ... ... 463 12,573 7.7 

Acute laryngitis and 

tracheitis . .... .. ... .... .... . ..... . .. 464 2,982 1.8 

Acute bronchitis and 

bronchiolitis . .... .... .. .. . ... .....466 5,326 3.3 

influenza ... . .. ... ...... ..... .... . ...470-474 10,312 6.3 

Pneumonia .. ...... . ... .... ... .. ....480-486 5,194 3.2 

Chronic diseases of the respiratory system .....490-493. 

502-503,507 59,722 36.5 

Bronchitis, unqualified, and 

chronic bronchitis ..... . 490-491 15,765 9.6 

Emphysema .... ... ... .. .... . . .. .. ...492 5,223 3.2 

Asthma .. .. ... ..... .. .. .. ... .. .... . ....493 10,951 6.7 

Chronic pharyngitis and 

nasopharyngitis . ...... .... .... .. 502 2,486 1.5 

Chronic sinusitis . .. ... ... . ... . .. . . 503 8,284 5.1 

Hey fever ... ..... ... . .. ... .. .. ..... ...5O7 17,012 10.4 

Other acute and chronic diseases of 

the respiratory system .. ...500.501. 

504-506,508,510-519 9,548 5.8 

1Tdased on the Eighth Revision International Classification of 

Diseases, Adapted for Use in the United States (ICDA). 

Influenza and pneumonia together accounted for approximately 10 percent of visits 

for respiratory diseases. Six chronic diseases of 

the respiratory system comprised an additional 

37 percent (table 1). Emphysema, asthma, and 

pneumonia were chiefly responsible for the visits 

classified as serious or very serious. A future 

report currently in preparation will provide additional indepth analysis of visits for specific 

respiratory diseases, and will be published in 

Series 13 of Vital and Health Statistics. 

Table 2 displays age and sex distributions of 

visits for selected diseases. Like most NAMCS 

visits, proportions of females visiting for most 

respiratory illnesses exceeded those of males. 

However, male visits clearly exceeded female 

visits when the illness was diagnosed as 

emphysema. 

Patients under 25 years of age were responsible for most of the visits for acute URl and for 

pneumonia. But patients over 25 years of age 

predominated the visits when the other respiratory diseases shown in table 2 were diagnosed. 

However, patients under 15 years of age represented about one-third of the visits for bronchitis and for asthma and about 29 percent of 

the visits for hay fever. Patients 65 years of age 

or older were responsible for the smzdlest proportions of visits for all respiratory conditions 

except emphysema. Patients 45 years of age and 

over were responsible for almost all visits for 

emphysema. 

Figure 2 highlights the high rate of office 

visits for acute UIU by patients under 15 years 

of age. For every 1,000 members of that age 

group in the population, there were 343 visits to 

a physician for acute URI. This number declined 

by half or more for patients up to 64 years of 

age and by about two-thirds for patients aged 65 

years or older. Figure 3 shows the average annual rate of office visits for influenza and for 

pneumonia. Figures 4 and 5 ilhr.strate three 

chronic conditions—bronchitis, asthma, and hay 

fever. 

When physician specialty data were examined, it was observed that general and family 

practitioners had the highest proportions of 

visits for acute URI, influenza, pneumonia, 

bronchitis, and emphysema (table 3). This observation is not a surprising result since general 

and family practice constitutes the highest 

proportion of office-based physicians in the 
-----

a&medaa3 

Table 2. Percent distribution of office visits for selected diseases of the respiratory system by age and sex of patient: 

United States. 1975-76 

II


II Age


Diagnosis and ICDA codel 

Acute upper respiratory infections .......... ..... 460-466 

influenza ........... ...... .............. ....................... 470.474 

pneumonia ....................................................48O.486 

Bronchitis, unqualified, and chronic 

bronchitis ................................................... 490.@ I 

Emphysem ............................. ....... .....................492 

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

Chronic pharyngitis, naspoharyngitis, and 

sinusitis .............................. .........................5O2.5O3 

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

sax 

, 

54.2 45.8 

47.0 53.0 

50.8 49.2 

57.9 42.1 

28.6 70.4 

54.9 45.1 

58.7 41.3 

56.3 43.7 

100.0


100.0


100.0


100.0 

100.0


100.0


100.0 

100.0 

Percent distribution 

46.0 14.4 18.9 15.0 5.8 

18.1 14.3 31.7 25.9 10.0 

37.7 12.4 17.1 20.3 125 

32.9 9.0 20.3 25.2 12.6 

*1.’I �0. I *4.8 44.9 49.0 

32.9 10.9 18.1 28.1 10.1 

13.8 14.4 34.6 25.4 11.8 

29.2 16.6 30.9 17.7 5.6 

1 Based on the Eighth Revision International Clmsification of Diseases, Adapted for Use in the United States (ICDA). 

United States.3 Internists treated a higher 

proportion of patients visiting for emphysema 

than they did those for other respiratory diseases and rvere responsible for the second 

3Goodman, L. J. and Mason, H. R. Physician Dktrs%utions and Medical Licensure in the U.S., 1975. Center for Health Services Research and Development. 

American Medical Association. Chicago, 1976. 

Figure 2. AVERAGE ANNUAL RATE OF OFFICE VISITS FOR ACUTE 

UPPER RESPIRATORY INFECTIONS (460-466), BY AGE OF 

PATIEN~ UNITED STATES, 197S-76 

50


t


o~ 

Under 15.24 25-34 3544 45-54 55.64 65 and 

15 over 

AGE IN YEARS 

highest proportion of \’isits for that problem. 

Since about t~vo-thirds of office visits to internists were by patients 45 years of age and over,4 

4NTat,ionalCenter for Health Statistics: Office Visits 

to Internists: N’ational Ambulatory Afedical Care Survey: 

United States, 1975, by Beulah K. Cypress. ilduance 

Data from Vital and Health Statistics, No. 16. DHEW 

Pub. No. (PHS) 7S-1 250. Public HeaIth Service, Hyattsvine, hld.,’Feb.’ 7, 1978. 

Figure 3. AVERAGE ANNUAL RATE OF OFFICE VISITS FOR 

INFLUENZA (470474) AND PNEUMONIA (46W86], BY 

AGE OF PATIENfi UNITED STATES, 1975-76 

—	 Pneumonia 

Influenza 

50 r 

o~ 

under 15-24 25-34 3544 45-54 55.64 65 and 

15 over 

AGE IN YEARS 
� 

4 aduancedata 

Figure 4. AVERAGE ANNUAL RATE OF OFFlCEVlSlTS FOR 

BRONCHITIS, UNQUALIFIED, AND CHRONIC BRONCHITIS 

(490491 ), BY AGE OF PATlENT UNITED STATES, 1975-76 

10


t


,~ Ulll 15-24 25.34 35.44 ‘%54 55.S4 65 and 

over 

AGE IN YEARS 

it is predictable that internists would see more 

respiratory problems related to the elderly, such 

as emphysema, than they would see acute URI, 

for example, where the visit rate was highest for 

the youngest age group. 

Allergists had the highest proportions of 

asthma and hay fever visits. 

Figure5. AVERAGE ANNUAL RATE OF OFFICE VISITS FOR HAY 

FEVER AND ASTHMA, BY AGE OF PATIENT UNITED STATES, 

—	 Hay fever 

. . . . . Asthma 

J I I I I I I 

un#r 15.24 25-34 3544 45-54 55.64 65 and 

over 

AGE IN YEARS 

Pediatricians treated about 22 percent of all 

patients visiting for asthma and 18 percent of 

“tiose visiting f&- hay fever. This acc&nted for 

58 percent of the visits made by patients under 

15 years of age for asthma and 49 percent for 

* 

Table 3. Percent distribut ion of office visits for selected diseases of the respiratory system, by physician specialty: 

United States, 1975-76 

Diagnosis and ICDA codel 

4cute upper Bronchitis, 

Physician specialty respiratory Influenza Pneumonia unqualified, Emphysema Asthma Hay fever 

infections (470-474) (480-486) a;:;:!t;; (492) (493) (507) 

(460-466) (490-491 ) I 

Percent distribution 

100.0 100.0 100.0 100.0 100.0 100.0 

78.5 50.5 56.9 52.4 29.5 26.3 

7.3 14.9 12.6 30.3 10.6 9.9 

8.8 27.0 20.6 *0.6 21.9 17.8 

*1.9 *3.3 *2.9 ++1.3 “0.7 *0.8 

*1.O ++0.3 *0.5 *0.6 *0.3 

*0.3 “0.4 *0.7 9.6 

“0.8 *3.1 32.3 30.6 

2.2 4.0 5.4 12.3 3.7 4.7 

I 

All specialties .............................. 

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

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

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

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

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

~ola~ngology ..................................... 

Allergy ................................................... 

All other specialties (residual) ................ 

100.0 

57.5 

7.8 

23.9 

2.9 

1.1 

3.1 

*0.4 

3.3 

1Based on the Eighth Revision Intematwnal Ckassificatwn of Diseases, Adapted for Use in the United States (lC?JA). 

I 
---

� dEmedaa5 

the same age group visiting for hay fever. The average duration of visits ranged from 

Higher than average proportions of visits for 11 minutes for acute URI to 17 minutes for 

respiratory conditions included drug therapy (70 emphysema. This time period hovered closely 

percent) and injections (27 percent). However, around the 15-minute average duration of all 

the blood pressure measurement rate of 24 per- estimated visits. 

cent was less than average. 

SYMBOLS 

Data not available——— 

Category not applicable—————-- . . . 

Quantity zero--———-

Quantity more than Obut less than 0.05—- 0.0 

Figure does not meet standards of * reliability or preeision 

‘\ 
6


TECHNICAL NOTES 

SOURCE OF DATA: The information presented 

in this report is based on data collected in the 

Nat ion al Ambulatory Medical Care Survey 

(NAMCS) during 1975 and 1976. The target 

population of NAMCS encompasses office visits 

within the conterminous United States made by 

ambulatory patients to physicians who are principally engaged in office practice. The National 

Opinion Research Center, under contract to 

NCHS, was the organization responsible for the 

survey’s field opera;ion. 

SAMPLE DESIGN: NAMCS utilized a multistage probability design that involves samples of 

primary sampling units (PSU’S), physician practices within PSU’S, and patient visits within 

practices. Each year a sample of practicing 

physicians is selected from master files maintained by the American Medical Association and 

the American Osteopathic Association. The 

1975-76 sample included 5,604 physicians with 

a response rate of 80 percent for the 2 years. 

These physicians were requested to complete 

Patient Records5 for a systematic random 

sample of office visits taking place within their 

5See figure L 

Figure 1. PATlENT RECORD 

ASSURANCE OF CONFIDENTIALITY—AII ,nformmon ~hlch ~o.(d ~ermd ,denm)camn d ,. ,nd,vld. al, I B~~ a P~=We. w m es~ablwhmm WII be held m. f,den!, al,w,(I b. used only by pe!mns m.aa.ged ,. md 10, the ~.rmse, of [he ,“mey and w,II no, be d,sclo,ed o, ml,,,ed ,. other per,.., or used %, any olhe, P“,w,e. 

1.	 DATE OF VISIT PATIENT RECORD 

NATIONAL AMBULATORY MEDICAL CARE SURVEY MFi%nfi­. 

2.	 OATf OF BIRTH 4. COLOR OR 

RACE 

I � WHITE 

M=#=7’+ 

3.	 SEX , D NEGRO/ BLACK 

I D FEMALE , � OTHER 

I , � MALE ‘ Z UNKNOWN 

5.	 PATIENT’S PRINCIPAL PROBLEM(S) 6. SERIOUSNESS OF 

COMPLAINT(S). OR SYMPTOM(S) ~ VISIT PROBLEM IN ITEM 5a 

{h ,rat,e.t’s own word,] (Check one) 

— ! ~ VERY SERIOUS 

, MOST 

IMPORTANT , ~ SE R1OUS 

I g SLIGHTLY SERIOUS 

b OTHER 4 b NOT SERIOUS 

7.	 HAVE YOU EVER SEEN 

THIS PATIENT BEFORE? 

s u Y~s ,ONO 

If YES, for the problem 

fndmoted m ITEM 5a ? 

~ ,1 YES ~ONO 

8.	 MAJOR REASON(S) FOR THIS VISIT (Ciwci all ma,.r mawv) 9. PHYSICIAN’S PRINCIPAL OIAGNOSIS ~ VISIT 

. DIAGNOSIS ASSOCIATED WITH ITEM Sa ENTRY 

U ACUTE PROBLEM . [. WELL ADULT! CHILO EXAM 

99 � ACUTE PROBLEM, FOLLOW-UP ~ .7 FAMII.Y PLANNING 

‘,7 � CHBONIC PROBLEM, ROUTINE r CO UN SE LING,ADVICE 

I. D CHRONIC PROBLEM, FLARE-UP ! m IMMUNIZATION 

, 0 PRENATAL CARE . [-] REFERRED BY OTHER PHYS/AGENCY b OTHER SIGNIFICANT CURRENT DIAGNOSES 

>S � POSTNATAL CARE c] ADMINISTRATIVE PURPOSE (In order of importance) 

. D POSTOPERATIVE CARE ~ ~ OTHER (.Soeu/y) 

-1 

( Operarwe procedure) I 10. DIAGNOSTIC/THERAPEUTIC SERVICES ONOEREO/PROVIOEO THIS VISIT fChsd#//thaf m) 11. DISPOSITION THIS VISIT 12. DURATION OF 

~ VISIT [ Time 01 � NONE 11 n DRUG PRESCRIBED [Check .// that apply) acr.dly spenf w!th 

02 � LIMITED HISTORY/EXAM 12 � X.UAY physician) 

03 � GENEilAL l+lSTORV/EXAM 13 � INJECTION @ NO FOLLOW-UP PLANNED 

04 � CLINICAL LAS TEST 14 a IMMUNIZATIONIDESE NSITIZATION i G RETURN AT SPECIFIED TIME 

05 � BLOOD PRESSURE CHECK 15 @ PHYSlOTh!ERAPY 3 L RETURN IF NE EOEO, PRN 

c+ � EKG 16 � MEDICAL COUNSELING 6 n TELEpHo NE FOLLOW. UP PLANNED 

MINUTES 07 � HEARING TEST 17 � mVCHOTHEFApVmHE flAPEUTIC ~ ~ REFERREO TO OTHER 

PHYSIC IA NIAGENCY 08 � VlS10r4 TEST LISTENING .; RETURNED TO REFk RR(NG 09 El EN005c0PY 18 G 0THE17 Specify) PHYSICIAN 

10 n OFFICE SURGFRV , :, ADMIT TO HOSPI IAL 

k ~ OTHER (@ecdy)_ 

I I I 

H RA-34-3 DEPARTMENT OF HEALTH, EDUCATION JIND WELFARE O.M. B. #6 S-S72106 

REV. S.74 PUBLIC HEALTH SERVICE EXpI RATION DATE 12i31f75 HEALTH RESOURCES ADMINISTRATION 

NATIONAL CENTER FOR HEALTH STATISTICS 
,.-

amcedaa7 

practices during a randomly assigned weekly reporting period. Participating physicians completed 114,000 Patient Records during the 2-

year period. Characteristics of the physician’s 

practice, such as primary specialty and type of 

practice, are obtained during an induction interview. .4 detailed description of the NAMCS 

design and procedures can be found in Series 13, 

Number 33 of Vital and Health Statistics. 

SAMPLING ERRORS: Since the estimates for 

this report are based on a sample rather than the 

entire universe, they are subject to sampling variability. The relative standard error of an estimate is primarily a measure of sampling variability. The relative standard error of the 

estimate is obtained by dividing the standard 

error of the estimate by the estimate itself and is 

expressed as a percent of the estimate. Relative 

standard errors of selected aggregate statistics 

are shown in table I. The standard errors appropriate for the estimated percentages of office 

visits are shown in table II. . ROUNDING: Aggregate estimates of office visits 

presented in the tables are rounded to the 

nearest thousand. The rates and percents, however, were calculated on the basis of original, 

unrounded figures. Due to rounding of percents, 

the sum of percentages may not equal 100.0 percent. 

Table 1. Approximate relative standard error of estimated 

nutiers of office visits, NAMCS 1975-76 

Relative standard 

Estimate in thousands error in 

percentage points 

wo ............................ ............................ 30.2 

l.ooo ........... .................... ...................... 23.5 

2.000 ........... ........ .................................. 16.7 

4.000 .... ................................................. 12.0 

lo.ooo ................................................... 8.0 

N.mo ................................................... 4.8 

2oo.ooo . ..... ..................... ..... ................. 3.4 

1.Mo.mo .... ................... .............! ......... 3.1 

Example of use of table: Arr aggregate estimate of 25,000,000 

visits has a relative standard error of 6.4 percent or a standard 

error of 1,600,000 visits (6.4 percent of 25,000,000). 

DEFINITIONS: An ambulatory patient is an individual presenting himself for personal health 

setvices who is neither bedridden nor currently 

admitted to any health care institution on the 

premises. 

An office is a place that the physician 

identifies as a location for his ambulatory 

patients. Responsibility over time for patient 

care and professional services rendered there 

generally resides with the individual physician 

rather than an institution. 

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 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 who specialize in anesthesiology, pathology, radiology; 

physicians who are federally employed; physicians who treat only institutionalized patients; 

physicians employed full time by an institution; 

and physicians who spend no time seeing ambulatory patients. 

Table 11. Approximate standard errors of percentages for 

estimated numbers of office visits, NAMCS 1975-76 

— 

8ase of percentage Estimated percentage 

(number of visits 1 or 5 or 10 or 20 or 30 or so in thousands) 99 95 90 80 70 

Standard error in percentage points 

600 ........................ 3.0 6.5 9.0 12.0 13.8 15.0 

1,000 ..................... 2.3 5.1 7.0 9.3 10.7 11.6 

2,000 ..................... 1.6 3.6 4.9 6.6 7.5 8.2 

4,000 ..................... 1.2 2,5 3.5 4.7 5.3 5.8 

10,000 ................... 0.7 1.6 2.2 2.9 3.4 3.7 

40,000, .................. 0.4 0.8 1.1 1.5 1.7 1.8 

200,000 ................. 0.2 0.4 0.5 0.7 0.8 0.8 

1 ,000,000, ............. 0.1 10.2 0.2 J__ 0.3 0.3 0.4

Example of use of table: An estimate of 20 percent based on 

an aggregate estimate of 80,000,000 visits has a standard error of 

1.3 percent. The relative standard error of 20 percent is 6.5 (1.3 

percent + 20 percent). 
No. 40 

No. 39. 

No. 38. 

Recent Issues of Advance Data 

Contraceptive Utilization Among Widowed, 

Divorced, and Separated Women in the United 

States: 1973 and 1976 (Issued September 22, 

1978) 

Office Vkits to Urologists, National Ambulatory Medical Care Survey: United States, 

1975-76 (Issued: September 7, 1978) 

Office Vk.its to Psychiatrists, National Ambulatory Medical care Survey: United States, 

1975-76 (Issued: September 7, 1978) 

From Vital and Health Statistics 

No. 37.	 Office Vkits to Dermatologists, NationsJ Arnbulatory Medical Care Survey: United States, 

1975-76 (Issued: August 25, 1978) 

No. 36.	 Contraceptive UtYlzation in the United States: 

1973 and 1976 (Issued: August 18, 1978) 

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

Information Branch. 

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