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

U.S. DEPARTMENT OF HEALTH, . Public Health Service


EDUCATION, AND WELFARE Office of Health Research, Statistics, and Technology Number 53 � September 11,1979


Office Visits Involving X-rays, National Ambulatory 

\ Medical Care Survey: United States, 19771 

Based on findings of the 1977 National Ambulatory hledical Care Survey, this report examines the use of X-rays by office-based physicians. An X-ray is defined as any single or 

multiple X-ray examination for diagnostic or 

screening purposes. Radiation therapy is not 

included. When the phrase X-ray visit appears in 

these pages, it applies to any office visit where 

an X-ray was either provided or ordered. � The National Ambulatory h’ledical Care Survey (NAMCS) is a continuing sample survey 

conducted annually by the Division of Health 

Resources Utilization Statistics of the National 

Center for Health Statistics. The survey-national 

in range except for Alaska and Hawaii-is designed 

to explore the provision and utilization of ambulatory care in the offices of non-Federal, officebased physicians. Since the statistics used in 

this report are based on a sample rather than on 

the entire universe of office-based physicians, 

they are estimates only and subject to sampling 

variability. Along with more information on the 

survey design and definitions of terms used in 

NAh4CS, the Technical Notes at the end of the 

report provide guidelines for iud,ging the precision of the estimates presented. 

DATA HIGHLIGHTS 

In 1977 an estimated 570,052,000 visits 

were made to office-based physicians within 

the NAMCS scope. An estimated 7.8 percent 

(44,662,000) of these were X-ray visits involving the provision or ordering of single or muIti0 1This report was prepared by Hugo Koch and 

Raymond O. Ga.gnon, Division of Health Resources 

Utilization Statisti&. 

ple X-ray examinations for diagnostic or screening purposes. 

Table 1 sho~vs the 15 reasons–that is, 

symptoms, compkints, or nonsymptomatic 

problems–most commonly moti~~ating patients 

to make X-ray visits; the reasons are ranked according to the frequency of X-ray visits associated with each. Note, however, that these were 

principal reas~ns ordy. Up to t~vo other reasons 

could have been given by the patient, often 

creating symptom clusters, which, though they 

are not analyzed in this brief report, undoubtedly 

influenced the physician’s choice of diagnostic 

mechanisms, including the use of .X-rays. As a 

,voup these 15 principal reasons accounted for 

43 percent of all X-ray visits: The importance 

of the .X-ray as a routine screening mechanism 

is evident from the finding that the Iarqest single 

block of X-ray visits (an estimated 2,815,000) 

was associated ~i~ithpatients’ requests for general 

medical examinations-annual physicaI examinations, routine checkups, etc. As a dia,g-nostic 

mechanism-clearly their chief role —~X-rays 

were applied most frequently to symptoms or 

complaints of the musculoskeletal system. Nine 

of the 15 reasons listed in table 1 center on 

musculoskeletal problems. 

Tables 2 and 3 focus attention on the involvement of X-rays in the physicians’ diagnoses of the symptoms presented by patients. 

As with the principal reasons motivating patients 

to make X-ray visits, these tabulations are based 

on the principal diagnoses only-that is, the diagnoses most closely linked to the chief problems 

presented by patients. Up to two other concurrent conditions could have been listed, and it is 

possible that the use of X-rays was prompted in 

whole or in part by the presence of these other 
� 

2 acklncedata � 

Table 1. Number and percent distribution of X-ray visits; number of all visits and percent involving X-rays, by the 15 leading principal 

reasons for visits given by patients (ranked according to the frequency of X-ray visits): United Statas, 1977 

Rank 

1


2 

3 

4 

5 

6 

7 

8 

9 

10 

11 

12 

13 

14 

15 

X-ray visits2 All visits 

Patient’s principal reason for 

Percent visit and NAMCS codel Number in Percent Number in 

thousands distribution thousands involving 

Total ..................................................................... 

Ganeral medical examination ... XIOO....................... Xl OO.O 

Back symptoms (excludes injuries) ...................... S905.0 

Chest pain end related symptoms (not 

referable to body syetem) .................................. SO5O.O 

bugh ............. ............ .. ....................................... S44O.O 

Knee symptoms-(excludes injuries) ...................... S825.0 

Abdominal pain, cramps, spasms ..........................s550.0 

Foot and toe symptoms (excludes injuries) ..........S835.0 

Low back symptoms (excludes injuries) ..... ......... S91 O.O 

Shoulder symptoms (excludes injuries) ................ S94O.O 

Neck symptoms (excludes injuries) ............ .......... S8OO.O 

Blood pressure teS .............................................. X32O.O 

Hip symptoms (excludes injuries) ........................S9l 5.0 

Headache ............................................................. S21 O.O 

Leg symptoms (excludes injuries) ............. ........... S92O.O 

Ankle symptoms (excludes injuries) ......... .. ......... S830.0 

All other reasons ...... ....................... ................ ... residual 

X-rays 

44,662 100.0 570,052 7.8 

2,815 6.3 20,659 13.6 

2,194 4.9 10,696 20.5 

1,801 4.0 8,388 21.5 

1,562 3.5 13,937 11.2 

1,459 3.3 5,309 27.5 

1,425 3.2 8,715 16.4 

1,239 2.8 3,976 31.2 

1,020 2.3 4,594 22.2 

944 2.1 4,388 21.5 

830 1.9 4,915 16.9 

822 1.8 14,990 5.5 

795 1.8 2,144 37.1 

771 1.7 9,458 8.2 

752 1.7 5,161 14.6 

707 1.6 1,873 37.7 

25,526 57.1 450,839 5.7 

18ssed on a classification of patients’ reasons for visits developed for use in N~CS. - -. . -. ‘An X-ray visit is any visit involving the use ot” a single or multiple X-ray examination for magnosuc or screening purposes. 

conditions. Table 2 shows the 15 specific diagnoses most commonly assigned to X-ray visits 

ranked according to the frequency of X-ray 

visits associated with each diagnosis. The importance of the X-ray as a screening mechanism 

is again reinforced by the finding that the largest 

single block of X-ray visits (2,037,000) was associated with preventive examinations. In their 

chief role of diagnostic mechanism X-rays were, 

predictably, most often used in association with 

musculoskeletal disease or injury. Note, for example, that 3 of every 5 visits for fracture of the 

radius or ulna involved the use of X-rays. TabIe 

3, by gathering all specific diagnoses into diagnostic groups, offers a broader perspective of the 

use of X-rays throughout the clinical spectrum. 

The diagnostic groups most commonly associated with X-ray procedures were accidents, 

poisonings, and violence; diseases of the musculoskeletal system; diseases of the digestive systems; and symptoms and ill-defined conditions. 

X-rays are generally applied early in the diagnostic process. This is confirmed by the findings 

in table 4, which show that most X-ray visits (54 

percent) occurred at the new-condition visit, 

that is, when the physician encountered a 

condition in a patient for the first time. This 

could be any condition presented by a new 

patient or any new condition presented by a 

patient already established as part of the doctor’s practice. Evidence for an overall conservatism in the diagnostic use of X-rays lies in the 

finding that, in the course of 1 year, an average 

new-condition visit that involved the use of an 

X-ray or X-rays entailed fewer than 1 (0.9) 

return visits at which X-rays were used (a 

rough approximation, obtained by dividing 

the 20,493,000 return visits involving X-rays by 

the 24,169,000 new-condition visits involving 

X-rays). 

X-rays were most likely to be applied with 

new patients referred by other physicians. As 

table 4 makes evident, the frequency with which 

X-rays were applied at referred visits–16.2 percent of the total 28,412,000 referred visits—was 

more than double the average frequency of 

X-ray use (in 7.8 percent of all visits). o 

Along the continuum of patient age, the in-
1

2

3

4

5

6

7

8

� 

� a&mcecw3 

Tabla 2. Numbar and percant distribution of X-ray visits; number of all visits and percent involving X-rays, by the 15 leading principal 

diagnoses assigned by physicians (ranked according to frequency of X-ray visits): Unitad States, 1977 

X-ray visits2 All visits 

Principal diagnosis and ICDA codel	 Number in Percent Number in Percent 

thousands distribution thousands involving 

Rank 

9 

10 

11 

12 

13 

14 � 15

Total .................... ............. ........................ ............ 

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

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

Osteoarthritis and allied renditions ...................... ... 713 

Medical and surgical aftercare ...... .............. ...............yl o 

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

Sprains and strains of ankle and foot ........................845 

Chronic ischemic heart diseese ...... ....... .....................4l2 

Sprains andstrains ofother and unspecified 

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

Bronchitis ...... .. ................ .. ...... .................................49O 

Fracture of radius and ulna .......................................81 3 

Sprains and strains of sacroiliac region .. ....................846 

Other illdefined and unknown causes of 

morbidity and momality ......... ................... .... .........796 

Fracture of one or more phalanges of hand .............. 816 

Other nonarticular rheumatism .................. ............. . 717 

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

All other principal diagnoses .............................. residual 

X-rays 

44,662 100.0 570,052 7.8 

2,037 4.6 41,716 4.9 

1,665 3.7 24,837 6.7 

1,431 3.2 5,866 24.4 

1,352 3.0 19,524 6.9 

1,078 2.4 5,331 20.2 

1,064 2.4 2,136 49.8 

911 2.0 11,943 7.6 

862 1.9 4,981 17.3 

842 1.9 6,597 12.8 

726 1.6 1,200 60.5 

661 1.5 2,478 26.7 

576 1.3 2,797 20.6 

565 1.3 1,056 53.5 

557 1.3 4,027 13.8 

527 1.2 17,925 2.9 

29,808 66.7 417,638 7.1 

1 Based on E&hth Revim-on International C7ass[fieation of Dr3euses, Adapted for L& in the United States (ICDA). 2~ x.ray ~i5it is any ~5it involv~g the “5e of a stigle or multiple X-ray examination for diagnostic or screening P~Poses. 

tensity of X-ray usage showed three conspicuous 

peaks (table 5). The first is noticeable in the 

injury-prone period of the teens; X-ray visits 

composed as much as 8.5 percent of all visits 

made by patients in this age interval. The second 

peak–the highest of the three–appears in the 

5-year span 55-59 years; here X-ray procedures 

were appIied at 11.1 percent of all visits. A third 

peak is evident in the interval from 70-74 years. 

The latter two peaks reflect the onset and X-ray 

diagnosis of the chronic, musculoskeletal diseases common to advancing years, the second 

peak being linked in large p&-t to the X-ray 

diagnosis of rheumatoid arthritis and the third 

to that of osteoarthritis. 

As a group, males were X-rayed at an estimated 9.6 percent of their visits, a proportion 

half again as high as the proportion of 6.7 percent found among females (table 5). Table 6 and 

figure 1 reveaI that this difference was especially prominent in the age interval 20-50 years; 

during this period the frequency with which 

men were X-rayed (at 11.9 percent of visits) . . ~iras about ttirice the freauencJz found for women 

(5.8 percent of visits). - ‘ 

In the sheer volume of X-ray procedures that 

they provided or ordered, the primary-care specialties of general, famiIy, and internal medicine 

accounted for the majority (56 percent) of all 

the X-ray visits made to office-based practitioners (table 7). However, in the relative frequency with which they employed X-rays, the 

most visited specialities are in a different order, 

more closely related to clinicaI focus than to 

primary-care function. From this point of view 

. orthopedic surgeons were by far the most active 

: users of X-ray procedures; they were foIlowed at 

, a respectable distance by internists, cardiovascular 

specialists, urologists, and generaI surgeons, each 

, of which exceeded the average tendency to use 

X-rays (at 7.8 percent of visits). 
� 

4 achmncedata � 

Table 3. Number of visits to office-based physicians, percent involving X-rays, and number and percent distribution of X-ray visits by 

diagnostic groups: United States, 1977 

All visits X-ray visits2 

Diagnostic group and ICDA codesl	 Number in Percent Number in Percent 

thousands involving thousands distribution 

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

Infective and parasitic diseases . ..........................................000-136 

Neoplasms . ............. ................ ....................... .....................140-239 

Endocrine, nutritional, and metabolic diseases ...................24O-279 

Mental disorders .................................................................29O.3l5 

Diseases of the nervous system and sense organs .................32O-389 

Diseases of the circulatory sy~em ...... ................................39O-458 

‘Diseases of the respiratory sywem ......................................46O-5l9 

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

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

Diseases of the musculoskeletal system .. ... .........................7l O-738 

Arthritis and rheumtism .................................. ............7l 0-718 

Symptoms and illdefined renditions ............... ..................78O-796 

Accidents, poisonings, and violence ................................ ... 800-991J 

Fratiures ...................................................................... 800-829 

Dislocations and sprains ............................................... 830-848 

Special conditions and examinations without sickness ...... YOO-Yl 3 

Other diagnoses and diagnosis “none” or unknown ............residual 

X-rays 

570,052 7.8 44,662 100.0 

22,668 2,8 643 1.4 

14,286 6.8 970 2.2 

24,287” 4.4 1,065 2.4 

24,522 2.4 579 1.3 

48,291 2.7 1,295 2.9 

54,702 7.8 48275 9.6 

82,466 5.9 4,879 10.9 

18,451 14.5 2,681 6.0 

36,473 5.1 1,864 4.2 

32,983 20.1 6,633 14.9 

17,665 16.9 2,982 6.7 

25,695 13.2 3,393 7.6 

43,761 25.8 11,281 25.3 

8,309 54.1 4,493 10.1 

14,044 29.2 4,105 9.2 

96,009 3.9 3,771 

45,458 2.9 1,334 

1 Based on Esghth Revision International Classification of Diseases, Adapted for Use in the United States, (ICDA)
 2An x-ray ~~lt is any ~sit involv~g the use of a single or multiple X-ray examination fOr diagnostic or screening PmPo~s.


Table 4. Number of visits to office-based physicians, percent involving X-rays, and number and percent distribution of X-ray visits by 

patient-condition status and referral status: United States, 1977 

All visits X-ray visitsl 

Patient-condition status and referral status	 Number in Percent Number in Percent 

thousands involving thousands distribution 

Condition status 

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

Old patient ............................................................ ........................... 

New condition .... ....... ....................... ............................... ............ 

Old condition ................................................................... ........... 

New-condition visit2 ......................................................................... 

Return visit ....................................................................................... 

Whether referred by another physician 

Yes .................................................................................................... 

No..................................................................................................... 

X-rays 

570,052 7.8 44,662 100.0 

87,230 13.2 11,551 25.9 

482,822 6.9 33,111 74.2 

142,037 8.8 12,618 28.3 

340,785 6.0 20,493 45.9 

229,267 10.5 24,169 54.1 

340,785 6.0 20,493 45.9 

28,412 16.2 4,600 10.3 

541,640 7.4 40,062 89.7 

1An X.ray visit is any visit involving the we of a single or multiple X-ray examination fOr diagnostic or Smeening PurPo*s. 

2&y visit bY a new patient, or any visit by an old patient invoh’ing a new condition. 
o 

Table 5. Number of visits to office-based physicians, percent involving X-rays, and number and percent distribution of X-ray 

visits by age and sex of patients: United States, 1977 

— 

All visits X-ray visitsl 

Age and sex Qumber Percent Jumber Percent 

n thou- wolving I thou- distrisands X-rays zmds bution 

Total ... .............. ;70,052 7.8 44,662 100.0 

advancedata 5 

Table 6. Number of visits to office-based physicians, percent involving X-rays, and number and percent distribution of X-rey 

visits by sex and age of patients: United Statesr 1977 

Age

— 

Under 6 years ..... ......... 

6-10 years .. .................. 

11-14 years .................. 

15-19 years ......... ....... .. 

20-24 years .................. 

25-29 years .................. 

30-34 years .................. 

35-39 years .................. 

40-44 years ............ ...... 

45-49 years .................. 

50-54 years ........... ....... 

55-59 years .................. 

60-64 years ........... ....... 

65-69 years ...... ............ 

70-74 years ........... ....... 

75-79 vears .................. 

� 

80 yea;s and over .. ...... 

— 

Sex

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

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

54,913 2.4 1,337 3.0 

27,266 5.1 1,393 3.1 

21,578 8.5 1,835 4.1 

39,507 7.8 3,070 6.9 

46,254 5.6 2,568 5.7 

46,808 7.0 3,263 7.3 

40,185 8,1 3,257 7.3 

30,653 8.8 2,690 6.0 

28,683 9.2 2,635 5.9 

33,280 9.8 3,251 7.3 

36,744 9.4 3,443 7.7 

37,910 11.1 4,213 9.4 

34,229 9.2 3,148 7.0 

32,136 10.0 3,208 7.2 

25,515 10.5 2,670 6.0 

18,385 8.7 1,601 3.6 

16,007 6.7 1,078 2.4 

)45,1 87 6.7 22,975 51.4 

?24,865 9.6 21,687 48.6 

1A ~.ray ~sit is any vtit involving the use of a ~ngle or 

multiple X-ray examination for diagnostic or screening purposes. 

Sex and age 

Total ................. 

Female 

Under 11 years ............ 

11-19 years ...... ....... .... 

20-29 years ...... ........... 

30-39 years ...... ........... 

40-49 years ................. 

50-59 years., ............... 

60-69 years ..... ............ 

70-79 years ................. 

70-74 years ........... 

75-79 years ............ 

80 years and over ........ 

Male 

Under 11 years ............ 

11-19 years .................. 

20-29 years .................. 

30-39 years .................. 

40-49 years .................. 

50-59 years .................. 

60-69 years .................. 

70-79 years .................. 

70-74 years ............. 

75-79 years ............. 

80 years and over ........ . 

All visits X-ray visitsl 

lumber Percent Wmber Percent 

I thou- involving I thou- distrisands X-rays sands bution 

70,052 7.8 44,662 100.0 

T 

39,599 3.1 1,221 2.7 

34,350 6.4 2,187 4.9 

65,436 4.0 2,599 5.8 

46,368 6.9 3,177 7.1 

38,530 7.5 2,898 6.5 

44,312 9.4 4,150 9.3 

38,515 8.8 3,398 7.6 

27,787 9.6 2,674 6.0 

15,945 9.7 1,552 3.5 

11,842 9.4 1,122 2.5 

10,289 6.5 672 1.5 

42,579 3.5 1,511 3.4 

26,735 10.2 2,718 6.1 

27,626 11.7 3,232 7.2 

24,47 0 11.3 2,770 6.2 

23,43 4 12.8 2,988 6.7 

30,341 11.6 3,506 7.9 

27,851 10.6 2,959 6.6 

16,11 2 9.9 1,596 3.6 

9,57 0 11.7 1,117 2.5 

6,54 2 7.3 *479 *1 .1 

5,71 8 *7.1 *406 *0.9 

1~ ~.ra ~ ~it fi ~nY visit involving the use of a single or 

multiple X-ray examination for diagnostic or screening purposes. 
6 achncedata � 

Table 7. Number of visits to office-based physicians, percent in- Hgural. PERCENT OF ALL OFFICE VISITS INVOLVING x-i3AyS, E)y SEX. 

volving X-rays, and number and percent distribution of X-ray AND AGE OF PATIENTS: UNITED STATES, 1977 

visits by physicianlspecia lties: United States, 1977 

I 13,0 

All visits X-ray visitsl 12,0 

F 

Physician specialty	 Number ‘ercent Number Percent 

i n thou- wolving ‘in thou- distrisands X-rays sends bution 

Total ................. 570,052 7.8 

Genaral and family 

practice ... .. .... .. . ....... . . . 222,919 6.9 15,331 34.3 

Internal medicine ... .. ... . 64,959 14.6 9,486 21.2 

Orthopedic surgery .. .. .. . 20,201 43.2 8,733 19.6 — Male 

General surgery ..... .... .. .. 36,124 9.5 3,443 7.7 . . . . . . . . Female 

Pediatrics .. .... ... . ..... .. .. ... 54,762 2.5 1,390 3.1 

Urology ... . ... .. .. .. ..... .. . ... 11.,205 10.3 1,154 2.6 01 I I I I I I [ I I I 

Obstetrics and Under ,1.,9 *o.2g 30.39 40.49 50.59 60.69 70.74 75.79 80 ow and

All 

gynecology ... . . ..... .. .. ... 49,273 1.8 882 2.0 11 

Card iovescu Iar disease.. 6,218 12.8 793 1.8 AGE IN YEARS 

Otolaryngology .. .... . .... . 15,716 4.1 640 1.4 

other specialties ...... 88,675 3.2 12,810 6.3 

Ifi x-ray ~i~t is any tisit involving the use of a single or 

multiple X-ray examination for diagnostic or screening purposes. 

TECHNICAL NOTES 

SOURCE OF DATA 

The information presented in this report is 

based on data collected by the National Ambulatory Medical Care Survey (NAMCS) from 

January-December 1977. The target universe of 

NAMCS is composed of office visits made within 

the coterminous United States to non-Federal 

physicians who are principally engaged in office 

practice and are not in the specialities of anesthesiology, pathology, or radiology. The National Opinion Research Center, under contract 

to the National Center for Health Statistics, was 

responsible for the survey’s field operation. 

SAMPLE DESIGN 

NAMCS utilizes 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 American Osteopathic Association. For 1977 a total of 3,000 physicians 

were included in the sample. Of those found 

eligible for the survey, 77.5 percent participated. 

Characteristics of the physician’s practice–for 

example, primary specialty and type and location of practice—were obtained or confirmed 

during an induction interview. Participating 

physicians were requested to complete encounter forms (Patient Records) for a systematic 

random sample of their office visits during a 

randomly assigned weekly reporting period. 

During 1977, 51,044 Patient Records were 

completed. The Record contained an item to be 

checked whenever the use of X-rays was ineluded in the diagnostic procedures ordered or 

provided at the visit. A total of 4,141 Record 

indicated the use of single or multiple X-ray8 

procedures. 
- - -

-------

SAMPLING ERRORS 

The standard error is primarily a measure of 

the sampling variability that occurs by chance 

because only a sample, rather than the entire 

universe, is surveyed. The relative standard error 

of an estimate is obtained by dividing the 

standard error of the estimate by the estimate 

itself and is expressed as a percentage of the 

estimate. Relative standard errors of selected ag~egate statistics are shown in table I. The 

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

Table 1. Approximate relative standard errors of estimated 

numbers of office visits, NAMCS 1977 

Estimated number of Relative standard 

visits in thousands error in percent 

29.0 

600 ..................... .. ........... ............................. 26.5 

1 .ooo............................................................ 20.7 

2.000 ..................c......................................... 14.9 

m5.000 ............................................................ 9.9 

1o.ooo..............m........................................... 7.6 

20.000 .......................................................... 6.1 

50.000 .......................................................... 4.9 

100,000 ........................................................ 4.5 

5oo.ooo ........................................................ 4.1 

.Lhatrrple of use of table: An aggregate estimate of 75,000,000 

visits has a reIative standard error of 4.7 percent or a standard 

error of 3,525,000 visits (4.7 percent of 75,000,000). 

Table il. Approximate standard errors of percentages of estimated 

numbers of office visits, NAMCS 1977 

Base of percentage 

Estimated percentage 

(estimated number of 

visits in thousands) 

EElzEEE 

500 .............................. 

800 .............................. 

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

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

5,000 ........................... 

10,000 ......................... 

20,000 ......................... 

50,000 ......................... 

100,000 ....................... 

500,000 ....................... 

Standard error in percentage points 

2.9 6.3 8.6 11.5 13.2 14.4 

2.6 5.7 7.9 10.5 12.0 13.1 

2.0 4.4 6.1 8.1 9.3 10.2 

1.4 3.1 4.3 5.7 6.6 7.2 

0.9 2.0 2.7 3.6 4.2 4.5 

0.6 1.4 1.9 2.6 2.9 

0.5 1.0 1.4 1.8 2.1 2: 

0.3 0.6 0.9 1.1 1.3 1.4 

0.2 0.4 O.e 0.8 0.9 1.0 

0.1 0.2 0.3 0.4 0.4 0.5 

e Exzmple of use of table: An estimate of 30 percent based on 

an aggregate of 15,000,000 visits has a standard error of 2.5 percent. The relative standard error of 30 percent is 8.3 percent (2.5 

percent + 30 percent). 

ROUNDING OF NUMBERS 

Estimates of office visits have been rounded 

to the nearest thousand. For this reason detailed 

figures within tables do not always add to totals. 

Percents were calculated on the basis of originaI, 

unrounded figures and wilI not necessarily agree 

precisely with percents which might be calculated from rounded data. . 

Ambdatoy patient.–An ambulatory pa- @

tient i; an individual presenting himself for 

personaI heaIth services who is neither bedridden #3J$ 

nor currently admitted to any health care ~2.jP institution on the premises. 

Office.–An office is a place that the physi- P 

cian identifies as a location for his ambulatory 

practice. Responsibility over time for patient 

care and professional services rendered there 

generaHy resides ~vith the individual physician 

rather than an institution. 

Physician.–A physician is a duly licensed 

doctor of medicine (N1.D.) or doctor of osteopathy (D.O. ). 

I.zisit.-A t~isit 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. 

X-ray. – An X-ray is any single or muItiple 

X-ray examination for diagnostic or screening 

purposes. Radiation therapy is not included. 

X-ray visit.–An X-ray visit is any office visit 

where an X-ray is either provided or ordered. 

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--—--—— 
8 dmcdata o 

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(Issued: August 30, 1979) ical Care Survey (Issued: April 13, 1979) 

No. 50.	 Office Visits by Black Patients, National Ambulatory Medical Care Survey: United States, 

1975-76 (Issued:July 23, 1979) 

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