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PUBLICATIONS!3RANCH‘1~1 < ~’w --7


EIMORML LIBRARY . .-


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

U.S. DEPARTMENT OF HEALTH, EDUCATION, AND WELFARE � Public Health SeN,ice I N.rnber42¤ October 31,1978 

Office Visits to Cardiovascular Specialists, National Ambulatory 

Medical Care Survey: United States, 1975-76’ 

Using data from the NationaI Ambulatory 

MedicaI Care Survey (NAMCS), this report describes an estimated 13,517,000 visits made to 

the offices of cardiovascular specialists over the 

2-year span from January 1975 through December 1976. NAMCS is 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 annualIy 

throughout the coterminous United States by 

the Division of Health Resources Utilization Statistics of the National Center for Health Statistics. The survey sample is seIected from doctors of medicine and osteopathy who are 

principally engaged in office-based patient-care 

practice. Excluded from the sample are an indeterminate number of physicians who render 

some office-based ambulatory care but whose 

patient-care activities are secondary to another 

primary role such as teaching, research, or 

administration. AIso excluded from the NAMCS 

scope are physicians who are hospital-based; 

those whose speciaIty is anesthesiology, pathology, or radiology; and physicians in the Federal 

Service. 

Because the estimates presented in this report are based on a sample rather than on the 

entire universe of office-based, patient-care 

physicians, they are subject to sampIing variability. See the Technical Notes for an explanation and for guidelines in judging the 

relative precision of estimates presented in this 

1This report was prepared by Hugo Koch, Division of 

Health Resources Utilization Statistics. 

report. The directions offered there also rmovide 

tl-k basis for judging the statistical signkcance 

of differences between estimates. 

DATA HIGHLIGHTS 

IVith their estimated 13,517,000 office visits 

in the 2-year span 1975-76, cardiovascular specialists were among the 13 specialists whq figured 

most prominently in the provision of officebased ambulatory care (see table 1). 

Vkit distributions in table 2 show an emphatic preference for the metropolitan practice 

locations, and indicate a slight preference for 

solo practice over multiple-member practice 

arrangements. In this choice of location and 

type of practice, visits to cardiovascular specialTable 1. Number of visits to office-based specialists, by type of 

specialty: United States, 1975-76 

Number of 

Specialty visits in 

thousands 

General and family practice ............. ...................... 460,297 

Internal mdicine ..... .................. ............. .............. 130,367 

P4iatrics ............................. .................. .. ...... ... ..... 107,085 

Obstetrics and gynecology ..... .............................. .. 97,070 

General surgery ................ ...................................... 77,259 

Ophthalmlogy ..... ................................ ..... ............ 53,959 

Orthopedic surgery .............. .................................. 47,152 

Dermtology .... .............................................. ........ 35,721 

Psychiatry .............................................. ........ ........ 30,616 

Otolaryngolqy .................................................... .. 27,192 

Urology ................. ................................................ 20,728 

Cbrdiovascukzr disease ....... ................ .................... 13,517 

Neurology . ............................................................. 3,784 
{ 

2 dmcdata 

* 

Tabla 2. Number and percent distribution of office visits to 

cardiovascular specialists, and parcant distribution of office 

visits to all specialists, by characteristics of the physician: 

United States; 1975-76 

Table 3. Nutier and percent distribution of office visits to 1 

cardiovascular specialists, and percent distribution of office 

visits to all specialists, by characteristics of the patient: 

AH visits ............ 

Location of 

practice 

Metropolitan area . ..... 

Non metropo Iitan 

araa ........................... 

Type of 

practice 

solo ............................. 

Other ........................... 

Visits to– 

w 

Percant distribution 

13,517 100.0 100.0 

12,690 93.9 73.3 

827 6.1 26.7 

7,064 52.3 60.0 

6,453 47.7 40,0 

l~~ed on an ~~timated I.1 55.900.000 visits made to all 

office-based physicians in 1975’and’ 1976. 

z~cation within a standard metropolitan Sk3tktiCd area 

(SMSA). Composition of SMSA’S does not reflect 1974 adjust ments. 

ists agree with the average fkdings for all visits 

to office-based practitioners. 

It is evident from the visit-age distributions 

in table 3 that cardiovascular problems become 

increasingly manifest with advancing age. Four 

of every 5 visits were made by patients 45 years 

old and over. The median visit-age (calculated 

from visit distributions rather than the individual patients who made the visits) was 59 

years, exceeding by 22 years the median visit age 

of 37 years characteristic of overall office-based 

practice. 

Visits to cardiovascular specialists were 

about equally divided between male and female 

patients, making cardiovascular disease one of 

the few office-based specialties where visits by 

males equalled or exceeded visits by females. 

The other notable exceptions were pediatrics, 

urology, and orthopedic surgery. 

Underscoring the chronic nature of much 

cardiovascular disease is the fkding that threeUnitad States, 1975-76 

Number of 

visits to 

Patient cardiocharacteristic vascular 

specialists 

n thousands 

All visits ............ 13,517 

— 

Aga

Under 25 years ............ 550 

25-44 years .................. 1,783 

45-64 years .................. 5,730 

65 years and over ........ 5,453 

— 

Sex

Female ........................ 6,766 

Male ............................ 6,751 

Prior visit status 

Naw patient ................. 1,547 

Old patient, new 

problem ..................... 1,903 

Old patient, old 

problem .............. ....... 10,067 

Visits to– 

Cardio- All vascular specia(istsl special ists 

Percent distribution 

4.1 33.2 

13.2 26,5 

42.4 25.1 

40.3 16.2 

50.1 60.4 

49.9 39.6 

e 

11.5 14.6-

14.1 23.2 

74.5 62.3 

1 Based on an estimted 1,155,900,000 visits mark to all 

office-based physicians in 1975 and 1976. 

fourths of the visits to cardiovascular specialists 

were made by persons who were already established patients of the doctor and who were 

returning with old problems (table 3, pn”or visit 

status). For the 3,450,000 visits at which a new 

problem was presented (i.e., the 1,547,000 visits 

by new patients plus the 1,903,000 visits by old 

patients with new problems), there were 

10,067,000 return visits, an average of 2.9 return visits per new problem per year. This return 

visit rate substantially exceeded the average of 

1.6 return visits per year common in overall 

office-based practice; indeed, among the most 

visited specialists, it was exceeded only by the 

rate for office-based psychiatrists. 

Table 4 shows the clinical content of cardiovascular office practice. The chronic circulatory 

ailments clearly dominate. Two of them, chronic * ischemic heart disease and essential benign 
� 

Table 4. Percent distribution of office visits to cardiovascular 

specialists by principal (first-listed) diagnoses rendered by 

the physician classified by I CDA category: United States, 

1975-76 

Percent Principal diagnosis and ICDA codel Distribution 

All principal diagnoses .... ............... ........ ‘2100.0 

Diseases of the circulatory system ....... ......390-458 51.1 

Other diagnoses .... ......................... ............. .......... .. 48.9 

Diseases of the respiratory system ........46O-5l 9 7.5 

Special conditions and examinations 

without sickness ... ............................. YOO-Yl 3 5.8 

Symptoms and illdefined conditions...7879696 5.7 

Diseases of the musculosketal system...7l O-738 5.0 

Endocrine, nutritional, and metabolic 

diseases ..................... ......................... 240-279 5.0 

Diseases of the digestive system ........... 520-577 4.5 

Other conditions .......... ............. ................ ..... ... 15.4 

Diseases of the circulatory system.. 390-458 100.0 

Chronic ischemic heart disease .............. ........... 412 37.0 

Essential benign hypertension ..................... ..... 401 21.2 

Symptomatic heart disease .............. ................ . 427 12.9 � Other ischemic heart diseases ........... .. 410,411,413 7.8

* 

Chronic rheumatic heart disease ...... ..........393-398 7.0 

Other diseases of the circulatory system... Residual 14.1 

lB~sed on Eighth Revision International Classification of 

Diease, Adapted for Usein the United States (lCDA). ??Based on 13,517,000 princiya I di~gnoses. 

hypertension, account for about 58 percent of 

the 6.9 million visits where cardiovascular morbidity was the plincipal (first listed) diagnosis. 

The vital screening function performed by the 

cardiovascular specialist is apparent in the substantial number of visits that resulted in the 

identification of a disorder other than a circulatory disease; e.g., the 1,000,000 visits diagnosed as respiratory disease and the 1,270,000 

dia~oses which were about equally divided 

between diseases of the digestive system and 

endocrine, nutritional, and metabolic diseases. 

Table 5 points up the unique intensity of 

diagnostic activity that is required in cardiovascular office practice: on the one hand, to 

screen cardiovascular symptoms (for example, 

chest pain), from similar symptoms that arise 

from other disorders; on the other hand, to 

monitor the usually prolonged course of a circulatory disease once the diagnosis is clearly established. 

ackmdaa3 

Table 5. Number and percent of office visits to cardiovascular 

specialists, and percent of office visits to all specialists, by 

selected diagnostic and therapeutic services provided: United 

States, 1975-76 

Number of Visits to– visits to 

Diagnostic and cardio- Cardiotherapeutic services vascular vascular All 

specialists specilaistsl 

in thousands specila ists 

Diagnostic service Percent 

Limited history and/or 

examination . .. ... . .. ... .. . 7,827 57.9 51.6 

General history and/or 

examination . .. ..... .. .... . 2,838 21.0 16.3 

Clinical laboratory 

test ... . ... .. .. ... .. ..... . .. ... . 3,614 26.7 22.8 

X-ray . ... .. .. .. .... .. ..... .. .... 2,241 16.6 7.6 

Blood pressure check... 9,679 71.6 33.2 

EKG .. .. .. .. .. .. ... . ... ... . ... .. 5,189 38.4 3.3 

Therapeutic service 

Drug prescribed .. . .. .. ... . . 5,725 42.4 43.6 

Injection .... .. .. ... .. . .... .. . . 889 6.7 13.1 

Counseling . .. .. ... .. . .... .. . . 2,095 15.5 13.0 

1 ~sed on an estimted 1,155,900,000 visits made to all 

of~lce-bwed physicians in 1975”and”l 976. 

Data on the seriousness of problems pres ented to the cardiovascular specialist predictably place a substantial proportion of 

problems (35 percent) in the serious-to-verysenous category, almost twice the proportion 

assigned this de,qree of seventy in overall officebased practice (table 6). 

Direct.Iy reflecting the chronic nature as well 

as the actual or potential seventy of most of the 

problems presented to them, cardiovascular 

specialists ended 3 of every 4 visits by scheduling a return visit at a specified time (table 6, 

disposz.tion). On the other hand, there is zdso 

evidence of a patient mobility which is greater 

than average. Due in Iarge part to the intensive 

diagnostic screening discussed above, about 8 

percent of visits to the cardiovascuktr specialist 

ended either in return to a referring physician or 

in referral to another physician or agency. 

Data on duration of visit (tabIe 6) indicate 

that the average face-to-face encounter between 

patient tid cardiovascular specialist probably 

lasted about 22 minutes, substantially exceeding 

the 15-minute average calculated in overzdl 

office-based practice. 
4 ackncedata 

Table 6. Number and percent distribution of office visits to cardiovascular specialists, and percent distribution of office visits to all 

specialists, by selected visit characteristics: United States, 1975-76 

Visit characteristic 

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

Seriousness of problem 

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

Slightly serious ................. ...... .................................... 

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

Disposition (selected actions) 

No followup .......................... ...................................... 

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

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

Telaphone followp ..................... ................................ 

Referred to other physician/agency ............................. 

Returnad to referring physician ................................... 

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

Duration of physician-patient encounter 

O minutes (no face-to-face enwunter with physician ... 

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

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

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

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

31 minutes or~re .................... ................ ....m............. 

Number of visits Visits to– 

to card iovescular 

specialists in Card iovescu Iar 

thousands I specia Iists I All specialists 

I 

Percent distribution 

13,517 100.0 100.0 

4,763 35.2 19.2 

5,187 38.4 32.3 

3,567 26.4 ‘ 48.5 

650 4.8 12.3 

10,253 75.9 60.2 

2,084 15.4 21.9 

580 4.3 3.5 

478 3.5 2.8 

615 4.6 0.9 

*267 *2.O 2.1 

I * 204 *1.5 1.8 

*290 *2.2 15.1 

2,467 18.3 31.5 

3,879 28.7 26.6 

4,735 35.0 19.5 

1,942 14.4 5.5 

l~sedon unestimated l,155,go0,000 fiitsmde toaUoffice-based physiCtin5in 1975 and 1976. 
..................................................

adwmdaa5 

TECHNICAL NOTES 

SOURCE OF DATA: The information presented


in this report is based on data collected in the


National Ambulatory MedicaI Care Survey


(NAMCS) during 1975 and 1976. The target uni­


verse of NAMCS is comprised of office visits


made within the coterminous United States by


ambulatory patients to non-Federa.I physicians


who are principally engaged in office practice


and are not in the specialties of anesthesiology,


pathology, or radiology. The National Opinion


Research Center, under contract to the National


Center for Health Statistics, was the organi­


zation responsible for the survey’s fieId oper­


ation.


SAMPLE DESIGN: NAMCS utilizes a multistage


probability design that involves samples of pri­


mary 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 hledical Association and the American


Osteopathic Association. (For the 2 year period


1975-76, a total of 152 cardiovascular specialists


were included in the sample. They achieved a


response rate of 73 percent.) Characteristics of


the physician’s practice, for example, primary


specialty and type of practice, are obtained dur­


ing an induction interview. The physicians are


requested to complete Patient Recordsz (brief


encounter forms) for a systematic random


sample of office visits during a randomly as-


signed weekly reporting period. (In the 2-year


period 1975-76, sampled cardiovascular special­


ists completed a total of 1,730 Patient Rec­


ords.) A detailed description of the NAMCS de-


sign and procedures has been presented in the


publication “The National Ambulatory MedicaI


Care Survey: 1975 Summary.”3


SAMPLING ERRORS: Because the estimates


for this report are based on a sampIe rather than


2A facsimile of the Patient Record appears as figure I. 

3 National Center for Health Statistics: The National 

Ambulatory Medical Care Survey, 1975 Summary, 

United States, January-December 1975. Vital and Health 

Statistics. Series 13-No. 33. DHEW Pub. No. (PHS) 

78-1784. Washington. U.S. Government Printing Office, 

Dec. 1977. 

on the entire universe, they are subject to 

sampling variability. The standard error is primarily a measure of sampling variability. The 

relative standard error of an estimate is obtained 

by dividing the standard error of the estimate by 

estimate itself and is expressed as a percent of 

the estimate. Relative standard errors of selected 

aggregate statistics are shown in tabIe I. The 

standard errors appropriate for estimated percentages of visits are shown in table II. 

Table 1. Approximate relative standard errors of estimated number of office visits: United States, 1975-76 

Estimated number Relative 

of office visits standard error 

in thousands in percent 

600 ............... .......................................... 30.2 

1,000 ...................................................... I 23.5 

2,000 ....... ............................................... 16.7 

4,000 ................... .. ...... ........................... I 12.0 

10,000 . . 8.0 

40,000 .................................................... 4.8 

200,000 .................................................. 3.4 

1,000,000 ........ ....................................... 3.1 

Example of use of table: An aggregateestimateof 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). 

Table II. Approximate standard errors of percentages of estimated 

number of office visits: United States, 1975-76 

1 

Estimated percent 

Base of percent 

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

i,


I 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 1.8 

200,000 ............... 0.2 0.4 0.5 ::; ;:: o.8 

1,000,000 ............ 0.1 ().2 ().2 0.3 13.3 0.4 

Example of use of table: An est irnate 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 percent (1.3 percent + 20 percent). 
6


DEFINITIONS: An ambulatory patient is an individua.1 presenting himself for personal health 

services who is neither bedridden nor currently 

admitted to any health care institution. 

An office is a place that the physician 

identifies as a location for his ambulatory 

practice. 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 ph ysician’s supervision for the purpose of seeking care and rendenng health services. 

A ~hvsician is a dulv licensed doctor of 

medicine ‘(M. D.) or docto~ of osteopathy (D. O.) 

currently in office-based practice who spends 

time in caring for ambulatory patients. Excluded 

from NAMCS are physicians who are hospital 

based; physicians who specialize in anesthesiology, pathology, or 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. 

Figure PATlENT RECORD 

ASSURANCE OF CONFIDENTIALITY—AI, ,nfc,rma,,on Wh,ch twuld J,erm,, ,dent,f,ca,,m of m ,md,v,dual, 

, P’.ctkce, m m ,,, abl,,hnmnt w,ll b, hold m“f,de”,,,l, w,tl be used ‘ml” b“ c,.:,.., engaged !“ and 10, 

the P“rpc,,e, .f the survey and WOII“o, be d,sclmed O, r,l,c,sed ,. O,M, p,,,.”, ., used ‘o, any OIhe, P“,m$e, 

1.	 DATE OF VISIT PATl ENT RECORD 

NATIONAL AMBULATORY MEDICAL CARE SURVEY 

B~g 

7.	 HAVE YOU EVER SEEN 

THIS PATIENT BEFORE7 

u YES zDNO 

t 

If YES, for the problem 

md,cated m / TEM 5a 7 

~ � YES zUNO 

.~ 

2.	 DATE OF BIRTH 4. COLOR OR 

RACE 

D WHITE 

-

3.	 SEX > ~ NEGROI 

BLACK 

~ n FEMALE I El OTHER 

, 0 MALE ‘ ij UNKNOWN 

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

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

[/. paltent’s own wordx] (Check one) 

‘ I ~ VERY SERIOUS 

a MOST 

IMPORTANT G SERIOUS 

n SLIGHTLY SERIOUS 

~— b OTHER_ . G NOT SERIOUS

8. MAJOR FIEASON{S) FOR THIS VISIT (C.$,d ,// m,,,, ,,,so,I,] 9. PHYSICIAN’S PRINCIPAL DIAGNOSIS ~ VISIT 

d DIAGNOSIS ASSOCIATED WITH ITEM 5.3 ENTRY 

~ ACUTE PROBLEM : WE LL ADu LTc HILD ExAhI 

. ,1 ACUTE PROBLEM, FOLLOW-UP . [- FAMIIY PLANNING 

‘ � CHRONIC PROBLEM. ROUTINE : COuNsELIPJG ADVICE 

, ~ CHRONIC PROBLEM. FLARE. UP _ IMMUNIZATION 

a PRENATAL CARE [; REFER IJSD BY OTHER PHYS/AGENCY b OTHER SIGNIFICANT CURRENT OIAGNOSES 

o C pOSTNATAL CARE , L] ADMINISTRATIVE PURPOSE (/. rxder of mportance) 

E POSTOPERATIVE CARE . L, OTHER (.$!2,. dyJ — -1 

— 

( Operate procedure) 

10. DIAGNOSTIC/THERAPEUTIC SERVICES OROEREO/PROVIOEO THIS VISIT (ChSC~#//th8la#P/”) 11. DISPOSITION ~ VISIT 12. OURATION OF 

0, � NONE


02 U LIMITED H15T0Rv/ExAM


03 c1 GENERAL HISTORYIEXAM


04 � CLINICAL LAB, TEST


05 � BLOOD PREssURE CHECK


06 0 EKG


07 � HEARING TEST


08 � VlS!0f4 TEST


09 � ENCQSCOPY


10 n OFFICE SURGFRY 

RA.34.3 

EV. 8-74 

II m 

12 � 

13 � 

14 � 

15 @ 

16 � 

17 U 

LB G 

DRuG pflESCRIEIED 

X-RAY


INJECTION


lMMUN12ATIONlEIES6NSITIZAT10N


PHYslOT+,ERApY


MEDICAL COUNSELING


P5YcH0THERAPYlTHE13 ApEuTIc


LISTENING 

OTHEFI I*<fy) 

(Check all thar apply)	 T&S VISIT ( Time 

.cr”a//y spent Id) 

phys,c,an] 

; NO FOLLOW UP PLANh ED 

.T RETURN AT SPECIFIED TIME 

0 RETURN IF NEEDEO, PRN 

L? TELEPHONE FOLLOW-UP PLANNED 

u RkFERRED TO OTHER _MINUTES 

PHYslcl AN ,AGENCY 

.- RETURNED TO REFh RRING 

f>~y~,c,A~ 

ADMIT TO HOSPlrAL 

— OTHER (Spe,,fy )_________

, 

: 

$ 

A 

s 

lt– 

DEPARTMENT OF HEALTH, EDUCATION ANO WELFARE O,M. E. #68-S 72106 PUBLIC HEALTH SERVICE EXPIRATION �ATE 12f31f75 HEALTH RESOURCES ADMINISTRATION 

NATIONAL CENTER FOR HEALTH STATISTICS 
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dwncecw7 

Recent Issues of Advance Data From Vital and Health Statistics 

No. 41. Office Vkits for Respiratory Conditions, Na- tory Medical Care Survey: United States, 

t io nal Ambulatory Medical Care Survey: 1975-76 (Issued: September 7, 1978)


United States, 1975-76 (Issued: September


29, 1978) No. 38. Office Vkits to Psychiatrists, National Ambu­


latory Medical care Survey: United States, 

No. 40. Contraceptive Utilization Among Widowed, 1975-76 (Issued: August 25, 1978) 

Divorced, and Separated Women in the United 

States: 1973 and 1976 (Issued: September 22, No. 37. Office Vkits to Dermatologists, National Am1978) bulatory Medical Care Survey: United States, 

1975-76 (Issued: August 29, 1978) 

No. 39. Office Vkits to Urologists, National AmbulaA co replete list of Advance Data From Vital and Health Statistics is available from the Scientific and Technical 

Information Branch. 

SYMBOLS 

Data not available 

Category not applicable . . . 

Quantity zero -

Quantity more than O but less than 0.05 0.0 

Figure does not meet standards of 

* reliability or precision