Datafrom the 

NATIONAL HEALTH SURVEY 

BloodPressurelevels of 

Children6-11Years: 

Relationshipto Age,Sex,Race,and 

SocioeconomicStatus 

UnitedStates 

Series 11 

Number 135 

Blood pressure measurements of children 6-11 years of age in the United 

States, 1963-65, are presented and discussed by age, sex, race, and 

socioeconomic status. 

DHEW Publication No. (HRA) 74-1617 

U.S. DEPARTMENT OF HEALTH, EDUCATION, AND WELFARE 

Public Health Service 

Health Resources Administration 

National Center for Health Statistics 

Rockville, Md. December 1973 
Vital and Health Statistics-Series 1 l-No. 135 

For sale by the Superintendent of Documents, U.S. Government Printing Office, Washington, D.C. 20402 - Price 60 cents 
NATIONAL CENTER FOR HEALTH STATISTICS 

EDWARD B. PERRIN, Ph.D., Director 

PHILIP S. LAWRENCE, Sc.D., Associate Director 

GAIL F. FISHER, Acting Assistant Directorfor Health Statistics Development 

WALT R. SIMMONS, M.A., Assistant Director for Research and Scientific Development 

JOHN J. HANLON, M.D., Medical Advisor 

JAMES E. KELLY, D.D.S., Dental Advisor 

EDWARD E. MINTY, Executive Officer 

ALICE HAYWOOD, Information Officer 

DIVISIONOF HEALTHEXAMINATIONSTATISTICS 

ARTHUR J. MCDOWELL, Director 

GARRIE J. LOSEE, Deputy Director 

PETER V. V. HAMILL, M.D., Medical Advisor, Children and Youth Program 

HENRY W. MILLER, Chief Operations and Quality Co&r02 Branch 

JEAN ROBERTS, Chief, Medical Statistics Branch 

SIDNEY ABRAHAM, Chief, Nutritional Statistics Branch 

COOPERATION 

In accordance with 

Survey, the Bureau of 

participated in the design 

first stage of the field 

processing. 

OF THE BUREAU OF THE CENSUS 

specifications established by the National Health 

the Census, under a contractual agreement, 

and selection of the sample, and carried out the 

interviewing and certain parts of the statistical 

Vital and Health Statistics-Series 1 I-No. 135 

DHEW-Publication No. (HRA) 74-1617 

Library of Congress Catalog Card Number 73-600256 
CONTENTS 

Introduction ................................... 

Blood Pressure Measurement .......................... 

Definition of Other Variables .......................... 

Age.. .................................... 

Race ..................................... 

Page 

1 

1 

2 

2 

2 

Family Income and Parental Education ................... 2 

Findings on Blood Pressure Levels ....................... 2 

Age ...................................... 2 

Sex.. .................................... 3 

Race ..................................... 3 

Socioeconomic Status ............................ 3 

Comparison of Blood Pressure Level Findings ................. 7 

Children and Adults ............................. 7 

HES Examinees and Children in Other Studies ................ 10 

Summary .................................... 12 

References ................................... 14 

List of DetaiIed Tables ............................. 15 

Appendix. Special Sources of Variation in the Measurement of Blood Pressure . 21 

Time of Examination ...................... 

Order of Measurement. ..................... 

Examiner Variability ...................... 

End-Digit Preference ...................... 

Parameter and Variance Estimation ................. 

21 

21 

21 

23 

23 

iii 
- - - 

SYMBOLS 

Data not available--__________--________------------------

Category not applicable _________-________------------- , . . 

Quantity zero ________________________________________------ _ 

1 Quantity more than 0 but less than 0.05----- 0.0 

Figure does not meet standards of 

reliability or precision ______________________________ * 
BLOOD PRESSURE LEVELS OF CHILDREN 6-11 YEARS: 

RELATIONSHIP TO AGE, SEX, RACE, AND 

SOCIOECONOMIC STATUS 

Noel S. Weiss, M.D., Dr. P.H.; Peter V. V. Hamill, M.D., M.P.H.; and Terence Drizda 

INTRODUCTION 

This report presents the distribution of blood 

pressure levels of U.S. children aged 6-11 years 

by age, sex, and race. Data were obtained in 

Cycle II of the Health Examination Survey 

(HES), which is one of the major programs of 

the National Center for Health Statistics (NCHS) 

concerned with assessingthe health status of the 

U.S. population. The program consists of a series 

of surveys in which information is obtained on a 

probability sample of the U.S. population 

through examination, interview, measurement, 

and testing. 

In Cycle II of the HES, a representative sample of all noninstitutionalized children 6-l 1 

years of age in the United States was obtained. 

From July 1963 through December 1965, the 

survey staff examined 7,119 children, 96 per­

‘Assistant Professor of Epidemiology and International 

Health, School of Public Health and Community Medicine, University of Washington, Seattle, Washington; Dr. Hamill is Medical 

Adviser, Children and Youth Programs, Division of Health Examination Statistics; Mr. Drizd is Analytical Statistician, Division of 

Health Examination Statistics. 

cent of the original sample of 7,417. A description of the sampling process, program operation, 

and response rates has been published previous1y.r The standardized examination, given 

during a single visit, was primarily concerned 

with assessing health factors related to growth 

and development. Additionally, measurements 

of visual and auditory acuity were made, and 

evidence of the presence of congenital abnormalities, ear-nose-throat conditions, heart disease, 

and neuromusculoskeletal abnormalities was 

sought. 

BLOOD PRESSURE MEASUREMENT 

The measurement of blood pressure was part 

of a general cardiovascular examination that, in 

addition to a medical history, included a pediatrician’s examination, an electrocardiogram, a 

chest X-ray, and an exercise-tolerance test. 

Blood pressure was measured indirectly with 

the use of a standard clinical sphygomomanometer, the instrument employed in all physicians’ 

offices and in most surveys of blood pressure. This 

method is completely accepted by the children 

being examined, and it provides results comparable with clinical experience. The disadvantage 

1 
of indirect blood pressure measurement is that 

the readings obtained in this way may differ 

from “true” values-i.e., from those obtained by 

direct (intra-arterial) measurement. The direct 

and indirect methods of measurement agree 

closely for systolic pressure if the blood pressure 

cuff size is appropriate to the examinee’s height 

and arm girth.:! For diastolic pressure, however, 

the agreement is not as good. In the HES, diastolic pressure was defined as the complete cessation of sounds. If the sounds failed to .disappear, the pressure at which muffling occurred 

was used. The use of this criterion tends to underestimate intra-arterial diastolic blood pressure. The criterion not employed in the Survey 

of the muffling of sounds alone introduces approximately the same amount of bias in the opposite direction.2 

Two measurements were obtained, one at the 

beginning of the physical examination and one 

after the electrocardiogram. During each one, 

the child was lying down. The four nurses who 

measured blood pressure observed the following 

guidelines: 

1. The cuff should be at least 20 percent 

wider than the diameter of the arm or 

cover approximately two-thirds of the 

arm. (An adult 13-cm. cuff and a pediatric 

9.5-cm. cuff were provided.) 

2. The examiner should be at eye level with 

the manometer. 

3. The meniscus should be checked weekly 

for zero calibration. 

4. While measuring, the rate of fall should be 

approximately 2-3 mm. Hg per heartbeat. 

5. Readings are to be made to the nearest 2 

mm. Hg. 

On the average, the first blood pressure measurement on an examinee was higher than the 

second (see appendix). Unless otherwise specified, the blood pressure values presented in this 

report are the average of the two measurements. 

Blood pressure readings were somewhat affected 

by the time of day and by the nurse who obtained the reading. These sources of bias are also 

discussed in the appendix. 

DEFINITION OF’OTHER VARIABLES 

The child’s age was determined from the birth 

certificate in 95 percent of the cases and from 

the statement of a parent in the remainder. 

When used subsequently in this report, the term 

“age” will refer to the child’s age at his last 

bi&hday., 

Three racial groups were defined: white 

(86.69 percent), Negro (13.87 percent), and 

other (0.45 percent). All three groups are included in references to all races, but separate 

data are presented for white and Negro children 

only. 

Family Income and Parental Education 

Annual family income and parental education 

were reported by one of the child’s parents in a 

household interview before the examination; details of the interview have been described previously.1 Annual family income is defined as the 

combined earnings of all members of the child’s 

household, and parental education, as the highest grade level attained by either of the parents 

or guardian(s). 

FINDINGS ON BLOOD PRESSURE 

LEVELS 

Age 

Systolic blood pressure among the children increased regularly by about 1.4 mm. Hg for each 

year of age (figure 1, table l), from a median 

level of 105.5 mm. Hg at age 6 to 113.0 mm. Hg 

at age 11. This increase was present for both 

boys and girls and for both white and Negro 

children. Other percentiles rose with age approximately the same amount as did the median (figure 2, table 1). In contrast, diastolic blood pressure increased only about 0.3 mm. Hg per year 

2 
I I I I I J 

6 7 a 9 10 11 12 

AGE IN YEARS 

Figure 1. Median systolic and diastolic blood pressure of U.S. 

children 6-l 1 years of age by age. 

of age and quite irregularly (figure 1, table 2). 

The median diastolic pressure was 66.1 m m. Hg 

for 6-year-olds; it rose to only 68.4 m m. Hg for 

lo-year-olds and fell to 67.2 m m. Hg for llyear-olds. The pattern was similar for both sex 

and race groups (figure 3, table 2). 

Sex 

In general, the blood pressure of girls in the 

age group 6-11 years was higher than that of 

boys. For systolic pressure (figure 4, table l), 

the boys’ median exceeded the girls’ only at age 

6, and after age 8 the girls’ escess increased 

steadily to a maximum difference of 2.6 m m. Hg 

at age 11. Diastolic blood pressure was higher 

for girls at ages 7-10, but higher for boys at ages 

6 and 11 (figu re 5, tabIe 2). The shape of the 

distributions of both systolic and diastolic pressure was nearly symmetrical for boys and girls 

(figures 2 and 3)-that for systolic skewed 

slightly toward higher values and that for diastolic skewed slightly toward lower values. 

Race 

The median systolic blood pressure of white 

children was lower than that of Negro children 

at age 6, about the same at ages 7 and 8, and 

greater at ages 9-l 1 (figure 6, table 1). Except at 

age 6, though, the differences were small, no 

greater than 1.5 m m. Hg. The median diastolic 

pressure of Negro children was higher than that 

of white children at each age (figure 7, table 2). 

The difference was about 2 m m. Hg at ages 6 

and 11 and less at intermediate ages. Because the 

nurse who measured the blood pressure of a high 

percentage of Negro children also tended to 

measure diastolic pressure lower than the other 

three nurses, the true diastohc pressure differences between the races may be slightly larger 

than the ones shown here (see appendix). The 

blood pressure distributions for both white and 

Negro children were approximately symmetricaI 

(figures 2 and 3). 

Figures 8 and 9 show the relationship of 

blood pressure to age for each of the four racesex groups. In general, white girls had the highest median systolic pressure, Negro boys the 

lowest. For most ages, the median diastolic pressure of girls of each race was higher than that of 

boys of the corresponding race, while the median diastolic pressure of Negro children of each 

sex was higher than that of white children of the 

corresponding sex. 

Socioeconomic Status 

There was no relationship of a child’s systolic 

or diastolic blood pressure to his family’s annual 

income (table 3). Systolic blood pressure tended 

to decrease with increasing parental education 

(table 4), but in neither white nor Negro children was this trend steady or of great magnitude. The largest difference, 1.8 m m. Hg, was 

that between the lowest and highest education 

3 
q 

13c Isow 

120 -

110 

100 

p 90 

4 A 

E 0 s+h--- IO 11 12 g 

z

0 

s 

0 13c 

d 

Li 

t; 

120 

110 

100 

90 

01 6 9 10 II I2 

AGE IN YEARS 

Figure 2. Percentile distribution of systolic blood 

13t 

I2C 

110 

100 

p go 

E d 

fi 0 

2 

Ki 

65 

8 

s

* 130 

0 

0’ 

iz 

5 

120 

110 

100 

90 

WHITE 

) 75th 

50th 

25th 

10th 

5th 

1__1 IO 11 I2 

95th 

NEGRO / 

I I I I I I 6 7 6 9 10 II I2 

AGE IN YEARS 

pressure of U.S. children by age, sex, end race. 

4 

I 
9l 

BOYS 

8C 

/-- 95th 

90th 

70 . -75ti 

-m 

60 . - 25th 

l80 

70 

60 

50 

A 

0, 

-lMh 

-5th 

I I I I I I I

6 7 8 9 10 11 12 

GIRLS 

90th 

/- 75th 

-50th 

-t 25th 

6 7 8 9 10 11 12 

AGE IN YEARS 

FQure 3. Percentile distribution of diastolic blood C‘ 

91IWHITE 

8l I7c l60 

I I I I I I I 6 7 8 9 10 11 12 

NEGRO 

- -50th 

- 25th 

I I I I I I I 6 7 8 9 10 11 12 

AGE IN YEARS 

pressure of U.S. children by age, sex, and race. 

5 
Girls 114 r 

113 ­

ii,, , , , , , 

6 7 8 9 10 11 12 

AGE IN YEARS 

Figure 4. Median systolic blood pressure of U.S. children by age 

and sex. 

6 7 8 9 IO 11 12 

AGE IN YEARS 

Figure 5. Median diastolic blood pressure of U.S. children by 

age and sex. 

groups among white .children. This inverse relationship with parental education was also true 

for diastolic pressure in white children, with a 

difference of 2.2 mm. Hg between the lowest 

and highest education groups. In Negro children, 

there was no appreciable variation of diastolic 

pressure with parental education. 

112 -

111 -

110 -

109 -

108 -

107 -

106 -

105 -

I I I I I I 

6 7 8 9 10 11 12 

AGE IN YEARS 

Figure 6. Median systolic blood pressure of U.S. children by age 

and race. 

I I I I I I I 

6 7 8 9 10 11 12 

AGE IN YEARS 

Figure 7. Median diastolic blood pressure of U.S. children by 

age and race. 

6 
ii 

6 

m White boys m Whiteboys 

m+rrm White girls IIIlIIITII White girls 

111 Negroboys 111 Negroboys 

I Cm Negro girls llccl Negro girls 

71r 115 

114 

113 

P . 112 

1 

3 111 

% 

ii 

: 110 

z 

m 109 

s 

d 6 7 a 9 10 11 12 

?; 106 

AGE IN YEARS 

z 

s 

E 107 

L 

106 

105 

L 1I 

Or 

6 7 a 9 10 11 12 

AGE IN YEARS 

Figure 8. Median systolic blood pressure of U.S. children by age, 

race, and sex. 

COMPARISON OF BLOOD PRESSURE 

LEVEL FINDINGS 

Children and Adults 

An adult’s blood pressure is an important predictor of his health. Not only can death result 

from hypertensive disease per se, but blood pressure elevation is associated 

in coronary, cerebral, and 

There is increasing evidence 

may be a causal one. 6 Age, 

with arteriosclerosis 

peripheral vessels.3-5 

that this association 

sex, and race are all 

related to adult blood pressure levels.’ y8 Thus, it 

is of interest to study blood pressure in children 

Figure 9. Median diastolic blood pressure of U.S. children by 

age, race, and sex. 

and teenagers in an attempt to find out when 

these age, sex, and race differences become manifest, which in turn might suggest reasons for 

their occurrenci. 

As is well known, the blood pressure of children is lower than that of adults. Table A compares the mean systolic and diastolic blood pressures of children aged 6-11 years examined 

during 1963-65 with those of the 1960-62 HES 

sample of adults. The children’s systolic and diastolic pressures are lower than those of the age 

group 18-24 years, the age group of the adults 

with the lowest blood pressure levels. Within the 

6-11-year age group itself, there is a consistent 

increase in blood pressure with increasing age, 

with the exception of diastolic pressure among 

11-year-olds. This increase in blood pressure 

levels with age may result partially from differences in arm girth, since arm girth increases with 

age among children and arm girth is smaller in 

children than it is in adults. The blood pressure 

increase may be caused by one or more normal 

processes of maturation, e.g., hormonal changes. 

Finally, as is probably true for adults, the age 

7 
-- 

Table A. Mean blood pressure in children aged 6-11 years and 

adults aged 18-74 years: United States, 196365 (children) 

and 196062 (adults) 

Mean blood pressure 

Age 

-iizqGz 

Children mm. Hg 

6-11 years .................... 109.9 66.6 

Adults 

18-24 years .................... 116.4 70.4 

25-34 years .................... 119.9 74.6 

3544 years .................... 125.6 79.3 

45-54 years .................... 133.8 82.6 

55-64 years .................... 143.6 84.0 

65-74 years .................... 154.8 82.5 

increase may be a result of increased peripheral 

resistance in sclerotic arteries caused by wear 

and tear over-the passage of time. A subsequent 

report in this series, in an attempt to distinguish 

between some of these factors, will consider 

more closely the relationship of blood pressure 

with arm girth, body mass, skeletal age, and 

chronological age. 

The distributions of both systolic and diastolic blood pressure in adults become progressively more skewed to the right with increasing 

age. The blood pressure distributions for ages 

6-11 years are consistent with this trend, being 

skewed even less than those of young adults, and 

are indeed almost symmetrical (figure 10). There 

was, however, a slight skew to the left (lower 

values) for the diastolic blood pressure distribution among the children, best seen in figure 3. 

This is probably due to the presence of children 

whose arterial sounds never disappeared, and in 

whom “muffling” of the sounds was heard only 

at a low pressure. 

It has been claimed by some that the skewing 

to the right of the adult blood pressure distribution represents the superimposition of two 

distributions, one for normal persons and another for those who are pathologically hypertensive.g If this hypothesis is accurate (and it is 

by no means universally acceptedlO), there 

would seem to be but a very few children aged 

6-l 1 years who fall into the second, abnormal 

distribution. 

As determined in the 1960-62 survey of 

adults (Cycle I of the HES), the blood pressure level of men is greater than that of women 

until ages 50-60 years. After these ages the 

blood pressure level of women is greater.’ 

Among those aged 6-11 years, however, . girls’ blood pressure is generally higher than 

boys, particularly for systolic pressure. In all 

likelihood, during puberty the blood pressure of 

boys increases faster than that of girls and exceeds it by the time they reach adulthood. An 

unlikely alternative is that some characteristic of 

this particular birth cohort of girls may predispose them to higher blood pressure than that of 

boys, and the difference between them will persist through life. The correct choice between 

these two hypotheses could be made by blood 

pressure measurements at subsequent points in 

time among representatives of this birth cohort. 

To a limited extent, such measurements have already been made: a sample of teenagers from 

the older half of this same birth cohort was examined during 1966-70 as part of Cycle III of 

the HES. These results will be published in a 

subsequent report. 

As eth the sexes, the relationship between 

the blood pressure levels of whites and Negroes 

is somewhat different in children than in 

adults. Among the adults measured by the HES, 

for all age and sex groups other than men aged 

18-24 years, both systolic and diastolic pressure 

were higher in Negroes than in whites.8 Among 

children aged 6-l 1 years, although the diastolic 

blood pressure at each age was higher in Negroes, there was no consistent difference in 

systolic pressure. The white-Negro difference in 

systolic pressure that was seen at individual 

years of age was not large and could be explained by sampling variability (for standard errors, see tables 1 and 2). At least for diastolic 

blood pressure, however, the data presented here 

provide a basis for the conclusion that the difference between whites and Negroes begins early 

in life. 

Cycle I of the HES found that adults with 

little education had a greater prevalence of hypertension than expected; the relationship of income level to hypertension was unc1ear.l 1 In 

children, blood pressure tended to be inversely 

8 
40 1 

6-l 1 YEARS 1824YEARS 

0 loo 150 2uo 0 loo 150 200 260 

SYSTOLIC BLOOD PRESSURE (mm. Hg) 40 40 

2544 YEARS 46.64 YEARS 65 YEARS AND OVER 

30 E 

0 100 150 200 260 0 1w 150 2oa 260 0 loo 150 200 250 

SYSTOLIC BLOOD PRESSURE (mm. Hgl 

Figure IO. Comparison of frequency distribution of systolic pressure by increasing age: United States, 1963-65 (children) and 

1960-62 (adults). 

related to parental education, but the associ- There was no relationship between a child’s 

ation was weak and probably of no importance. blood pressure and his family’s annual income. 

9 
HES Examinees and Children in Other Studies 

Data from four studies of blood pressure in 

childhood have been selected for comparison 

with those presented here. Only one study, that 

reported by Johnson et al.’ * on the children of 

Tecumseh, Michigan, chose subjects that were 

representative of a well-defined population 

group, and none had the demographic breadth 

of the HES sample. Nonetheless, in each of the 

four studies blood pressure was measured in a 

standardized manner, and in each one a sufficient number of children were examined so that 

the sample estimates were reasonably stable. A 

summary of these and other design characteristics is presented in table B. 

Theoretically, a comparison of a number of 

studies of children can demonstrate how a particular characteristic, e.g., height or blood type, 

is related to the place or the point in time in 

which they live. However, because the measurement of blood pressure is so readily affected by 

the examiner, the equipment, and the conditions 

of examination, the presence of small differences in the absolute levels of blood pressure 

observed in the various studies is probably of 

little significance. But, as can be seen in figures 

11-13, some between-study differences were 

quite large. For systolic pressure, the means observed by Faber and James1 3 and by Graham et 

al.’ 4 for 6-year-old children were, respectively, 

12 and 6 mm. Hg lower than those observed by 

the HES. In 1 l-year-old children the differences 

between studies were smaller, due to the fact 

that the increase in systolic pressure with age 

was less in the HES than in these other studies. 

Overall, the HES figures were considerably more 

in agreement with the more recent data of 

Johnson et a1.l * ‘and L0nde.l 5 Since these latter 

studies and the HES took place at a later time, 

there possibly has been an increase in the systolic blood pressure levels among U.S. children 

over the past 50 years. However, because the 

samples of children drawn by each of the studies 

were so dissimilar, and because of the sources of 

measurement variation mentioned previously, 

such a conclusion cannot be made with much 

confidence. A subsequent report will explore in 

more detail the possibility of a secular trend in 

blood pressure levels of children. 

The diastolic blood pressure levels observed in 

the various studies differed little (figures 12, 

13), with the exception ‘of those of Graham et 

a1.l 4 That study used disappearance of sounds 

as the criterion for diastolic pressure, as did all 

others except one (table B). Even with the use 

Table B. Design characteristics of HES and four other selected studies of blood pressure in children

- - Author Time of study 

Examinees 

Source Number (6-I 1 years) 

r Method of 

measurement 

Faber and James (ref. 13) Before 1920 School children, 570 Two examiners, child 

California sitting, diastolic= 

muffling 

Graham et al. (ref. 14) 192640 School children, 3.500 One examiner, child 

Minnesota (9,901 measurements) sitting, diastolic= 

disappearance 

Johnson et al. (ref. 12) 1960 Children of 1,325 49 examiners, child 

Tecumseh, Mich. sitting, diastolic= 

disappearance 

Londe (ref. 15) Not stated Healthy children seen 824 One examiner, child 

(published in physician’s office supine, diastolic= 

in 1966) and clinic, St. Louis disappearance 

T 

Health Examination Survey, 196365 U.S. population sample 7,119 Four examiners, child 

Cycle II supine, diastolic= 

disappearance 

10 
110 -

FABER AND JAMES 

B 95 - 8 +#@ 95 -

E go- 90 -

i 

$ I I I I I 1 I I I I I I 

L

E 6 7 8 9 10 11 12 6 7 8 9 10 11 12 

id 

0 Girls 

z

2 120 - S* Girls 120 - 8

0 

2 ,.*’ )’ 0* 

: 115 - ,**$* Boys 115 - r* -I Boys 

,.,rW,, #i@* 

llO’- +G** 110 - 8 

/ 

* 

105 - ,05 _ &#$s uuy*I 

JOHNSON ETAL. *+ LONDE ** 

I I I I I I I I I I I I I 

6 7 6 9 10 11 12 6 7 0 9 10 11 12 

AGE IN YEARS AGE IN YEARS 

Figure 11. Mean systolic blood pressure of children by age and 5ex: Four prior studies. 

of the same criterion, however, diastolic pressure creased neither as much nor as regularly. These 

is particularly susceptible to observer variability; findings are quite similar to those of the HES. 

therefore, probably no further meaning should Three of the four studies provided mean 

be attached to the difference between that study blood pressure values by sex as well as by age. 

and the others. At age 6, systolic pressure in boys was found to 

No matter what ambiguities exist in inter- be greater than or equal to that in girls; at ages 

preting differences in absolute levels, it is none- 7-l 1, the girls’ systolic pressure tended to be 

theless valid to compare the relationships be- higher (figure 11). For diastolic pressure, Faber 

tween blood pressure distributions among and James1 3 found girls’ levels to be higher, the 

groups of children, e.g., age or race groups, that difference between the sexes increasing with age 

are observed within each of the studies, to see (figure 12). Londe r 5 observed the girls’ diastolic 

how these relationships vary or how widely they pressure to be higher than boys, except at age 

can be generalized. Figure 11 shows that in aI1 10. Among the children of Tecumseh, Michigan, 

four previous studies systolic blood pressure in- Johnson et al. 12 found no consistent difference. 

creased in a nearly linear way with age. Diastolic Again, the HES data are reasonably in accord 

blood pressure increased with age as well (figure with these earher findings: systolic pressure was 

12), though compared to systolic pressure it in- higher for girls after age 6 and particularly at . 

11 
75 - 75 r 

FABER AND JAMES Girls GRAHAM ET AL. 

70 - 70 -

65 -

60 - 60 -

B 

55 -

I I I I I I I I I I I I 

7 8 9 10 11 12 6 7 8 9 10 11 12 

:: 

s 

m 

0 

75 -

Girls BOYS LONDE 

% 

z

2 70 - 70 - Girls 

I 

65 - 65 -

JOHNSON ET AL. 

60 - 60 -

I I I I I I I I I I I I 

6 7 8 9 10 11 12 6 7 8 9 10 11 12 

AGE IN YEARS AGE IN YEARS 

Figure 12. Mean diastolic blood pressure of children by age and sex: Four prior studies. 

ages 9-l 1, while .diastolic pressure was generally 

higher for girls, but not uniformly so. 

None of these four studies, nor any others 

encountered, had sufficiently large numbers of 

Negro children to allow comparisons with the 

racial differences presented in this report. 

SUMMARY 

This report presents national estimates of 

blood pressure levels of children aged 6-l 1 years, 

based on findings of the Health Examination 

Survey of 1963-65. 

In the HES, a nationwide probability sample 

of 7,417 children was selected to represent the 

approximately 24 million noninstitutionalized 

children 6-11 years of age in the United States. 

Of those selected, 7,119 children (96 percent) 

were examined. 

Two measurements were obtained on each 

child with .the use of a sphygmomanometer. A 

standard set of procedures was followed by each 

of the four nurses responsible for the 

measurements. 

The children’s blood pressure levels were 

found to be lower than those of adults examined 

in the HES’ of 1960-62. Among the children, 

systolic blood pressure was higher in each successive age group, while diastolic blood pressure 

showed a less striking and more irregular 

increase. 

Differences between the blood pressure levels 

of boys and girls were small. After age 6, girls 

generally had a higher systolic pressure, the 

12 
m Faber and James 

m Graham et al. (sexes combined) 

I j Johnson et al. 

fTT?l Londe 

w HES Cycle II 

GIRLS 

I n 

6 7 8 9 10 11 7 8 9 10 11 

AGE IN YEARS 

11 6 7 8 9 

AGE IN YEARS 

Figure 13. Comparison of mean systolic and diastolic blood pressure of children in HES and four selected studies by age and sex. 

largest difference of 2.6 m m. Hg occurring at 

ages 10-l 1. Diastolic pressure tended to be 

higher in girls as well, but the sex differences 

were neither as large nor as consistent across 

each year of age as those for systolic pressure. 

Negro children had consistently higher levels of 

diastolic pressure than did white children, the 

largest difference being about 2 m m. Hg. For 

systolic pressure there was little difference between races. 

The children’s blood pressure showed a weak 

inverse relationship to parental education and no 

relationship to annual family income. 

The relationship of blood pressure to age and 

sex observed in the HES data is quite similar to 

that observed in earlier studies of blood pressure 

of children in the United States. Though there is 

a discrepancy between the absolute blood pressure levels obtained in the HES and in studies 

conducted several decades ago, the levels in the 

Survey are- in close agreement with those obtained in more recent studies. 

13 
REFERENCES 

1National Center for Health Statistics: Plan, operation, and 

response results of a program of children’s examinations. irital 

and Health Statistics. PHS Pub. No. 1000~Series I-NO. 5. Public 

Health Service. Washington. U.S. Government Printing Office, 

Oct. 1967. 

~MOSS, A. J., and Adams, F. H.: Heart Disease in Infants, 

Children, and Adolescents. Baltimore. The Williams & Wilkins 

Co., 1968. 

‘Gordon, T., and Kannell, W. B.: Predisposition to atherosclerosis in the head, heart, and legs. JAMA 221:661-666, 1972. 

*Paffenbarger, R. S., Laughlin, M. E., Gima, A. S., et al.: 

Work activity of longshoremen as related to death from coronary 

heart disease and stroke. N.Eng.J.Med. 282:1109-1114,197O. 

5Epidemiology Study Group: Epidemiology for stroke facilities 

f! 

lanning. Stroke 3:360-371, 1972. 

Veterans Administration Cooperative Study Group on 

Antihypertensive Agents: Effects of treatment on morbidity in 

hypertension. JAMA 202:116-122, 1967. 

7National Center for Health Statistics: Blood pressure of 

adults by age and sex, U.S. 1960-62. Vital and Health Statistics. 

PHS Pub. No. lOOO-Series 1 I-No. 4. Public Health Service. 

Washington. U.S. Government Printing Office, June 1964. 

8National Center for Health Statistics: Blood pressure of 

adults by race and area, U.S. 1960-1962. Vital and Health Statistics. PHS Pub. No. 1000~Series 11-No. 5. Public Health Service. 

Washington. U.S. Government Printing Office, July 1964. 

gPlatt, R.: Essential, hypertension: Incidence, course, and 

heredity.Ann.Int.Med. 55:1-11, July 1961. 

“Pickering, G.: High Blood Pressure. New York. Grune and 

Stratton, Inc., 1968. 

‘lNationa1 Center for Health Statistics: Hypertension and 

,hypertensive heart disease in adults, U.S. 1960-1962. Vital and 

Health Statistics. PHS Pub. No. lOOO-Series 1 l-No. 13. Public 

Health Service. Washington. U.S. Government Printing Office, 

May 1966. 

12J o h nson, B. C., Epstein, F. H., and Kjelsberg, M. 0.: Distributions and familial studies of blood pressure and serum cholesterol levels in a total community-Tecumseh, Michigan.J.Chron. 

Dis. 18:147-160, 1965. 

13Faber, H. K., and James, C. A.: The range and distribution 

of blood pressures in normal children. Am&.J.Dis.ChiZd. 

22:7-28,192l. 

14Graham, A. W., Hines, E. A., and Gage, R. P.: Blood pressures in children between the ages of five and sixteen years. 

Amer.J.Dis.Child. 69:203-207, 1945. 

“Londe, S.: Blood pressure in children as determined under 

office conditions. Clin.Peds. 5:71-78,1966. 

16National Center for Health Statistics: Replication: An 

approach to the analysis of data from complex surveys. Vital and 

Health Statistics. PHS Pub. No. 1000~Series ~-NO. 14. Public 

Health Service. Washington. U.S. Government Printing Office, 

Apr. 1966. 

14 
LIST OF DETAILED TABLES 

Page 

Table 1. Systolic blood pressure of children by race, sex, and age at last birthday: Selected percentiles, standard error of the 

median, sample sizes, and mean, United States, 196365 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 

2. Diastolic blood pressure of children by race, sex, and age at last birthday: Selected percentiles, standard error of the 

median, sample sizes, and mean, United States, 196365 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 

3. Median systolic and diastolic blood pressure in children aged 6-11 years by annual family income and race of child: 

United States, 196365 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 

4. Median systolic and diastolic blood pressure in children aged 6-11 years by education of parent and race of child: 

United States, 196365 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 

15 
Table 1. Systolic blood pressure of children by race, sex, and age atlastbirthday: Selected percentiles,standard error of the median, 

sample sizes,and mean, United States, 196365 

Percentile 

Race,sex,and age S50th n N x 

5th 10th 25th 50th 75th 90th 95th 

All races mm.Hg 

Both sexes,6-11 years . . 96.6 99.3 103.9 109.4 115.2 121.2 125.4 0.30 7,119 23;784 109.9 

D 

6years ................. 92.8 95.3 100.1 105.5 111.1 115.9 119.7 24 1,111 4,098 105.9 

7years ................. 95.6 98.4 102.3 107.3 112.2 118.5 121.5 .43 1,241 4,084 108.0 

8years.. ............... 97.0 99.5 104.0 109.1 114.2 119.8 124.0 .31 1,231 3,986 109.5 

9years.. ............... 98.6 100.9 105.3 110.2 116.1 121.1 125.3 .46 1,184 3,957 110.9 

loyears.. .............. 

Ilyears ................ 

99.1 

100.6 

101.8 

102.6 

105.8 

107.2 

111.1 

113.0 

117.7 

119.4 

122.8 

125.6 

126.3 

130.1 

.23 

.44 

1,160 

1,192 

3,867 

3,792 

111.9 

113.7 

Boys,B-11 years ...... 96.5 99.3 103.8 108.9 114.4 120.1 123.8 0.32 3,632 12,081 109.4 

6years.. ............... 92.4 95.6 100.3 105.7 111.0 115.6 119.8 .84 575 2,082 106.0 

7years ................. 95.7 98.2 102.3 107.1 111.9 118.0 121.2 .52 632 2,074 107.8 

8years ................. 97.4 99.9 104.2 109.1 114.0 119.0 122.8 .34 618 2,026 109.4 

9years ................. 98.9 100.9 104.9 109.3 115.2 120.8 124.6 .49 603 2,012 110.3 

loyears.. .............. 98.6 101.0 105.0 110.2 116.3 121.2 124.3 .29 576 1,963 110.8 

llyears ................ 99.5 102.1 106.7 112.0 117.3 122.6 126.9 .50 628 1,924 112.4 

Girls,6-11 years ...... 96.6 99.3 104.1 109.9 116.1 122.3 126.8 0.31 3,487 11,703 110.5 

6years ................. 93.3 95.1 99.9 105.2 111.1 116.3 119.4 .52 536 2,016 105.8 

7years ................. 95.4 98.6 102.5 107.7 112.8 119.0 121.9 .53 609 2,010 108.2 

8years ................. 96.7 98.8 103.6 109.2 114.3 120.4 125.5 .40 613 1,960 109.6 

9years ................. 98.1 100.9 105.9 110.9 116.8 122.0 126.9 .55 581 1,945 111.5 

loyears.. .............. 100.2 102.8 107.1 111.9 118.8 124.3 128.3 .41 584 1,904 113.1 

11 years.. .............. 101.1 103.0 108.3 114.6 121.4 128.1 131.8 .62 564 1,868 115.1 

White 

Both sexes,6-11 years . . 96.6 99.3 103.9 109.4 115.4 121.3 125.6 0.30 6,100 20,403 109.9 

6years ................. 92.4 95.2 99.9 105.1 110.9 115.3 119.1 .47 950 3,509 105.6 

7years ................. 95.6 98.6 102.3 107.3 112.3 118.7 121.8 .38 1,063 3,497 108.0 

8years ................. 97.0 99.6 104.0 109.1 114.2 119.9 124,l .31 1,035 3,413 109.6 

9years ................. 98.8 100.9 105.3 110.6 116.3 121.3 125.6 .53 1,019 3,393 111.0 

loyears.. .............. 99.2 101.8 105.9 111.2 117.8 123.0 126.4 .30 1,014 3,324 112.1 

Ilyears ................ 100.7 102.6 107.4 113.1 119.4 125.7 130.2 .49 1,019 3,267 113.8 

Boys,B-11 years ...... 96.6 99.2 103.8 108.9 114.6 120.2 123.9 0.30 3,153 10,391 109.4 

6years ................. 92.2 95.3 99.9 105.2 110.8 115.1 118.3 .65 489 1,787 105.5 

7years ................. 95.4 98.3 102.3 107.2 112.0 118.1 121.4 .46 551 1,781 107.8 

8years ................. 97.1 100.0 104.3 109.0 114.0 119.3 123.0 .36 537 1,739 109.5 

9yaars ................. 99.1 100.9 104.8 109.6 115.6 120.8 124.1 .65 525 1,730 110.4 

loyears.. .............. 98.7 100.9 105.0 110.5 116.3 121.6 124.7 .38 509 1,692 110.9 

11 years ................ 99.9 100.2 106.9 112.1 117.6 122.9 127.0 .52 542 1,662 112.6 

NOTE: sSOth = standard error of the median, n = sample size, N = estimated number of children in population in thousands, 

k= mean. 

16 
Table 1. Systolic blood pressure of children by race, sex, and age at last birthday: Selected percentiles, standard error of the median, 

sample sizes, and mean, United States, 1963-65-Con. 

-

Percentile 

Race, sex, and age '50th n N F 

5th 1 10th 1 25th 1 5Otb 1 75th 1 90th 1 95th 

White-Con. mm. Hg 

Girls, 6-I 1 years ...... 96.6 99.4 104.1 109.9 116.2 122.5 

/

127.0 0.37 2,947 IO,01 2 110.6 

6 years ................. 92.9 95.1 100.0 105.1 111.0 116.3 119.2 .48 461 1,722 105.7 

7 years ................. 95.8 98.7 102.5 107.6 112.9 119.0 122.1 23 512 1,716 108.2 

8 years ................. 96.6 99.1 103.6 109.3 114.5 120.3 125.3 33 498 1,674 109.7 

9 years ................. 98.2 101.0 106.0 111.1 116.9 122.8 127.6 .65 494 1,663 711.7 

IO years ................ 100.4 102.9 107.2 112.2 119.0 124.6 128.7 24 505 1,632 113.3 

11 years ................ 101.1 103.0 108.5 114.6 121.6 128.3 131.8 .63 477 1,605 115.2 

Negro 

Both sexes, 6-11 years . . 96.3 98.9 104.1 109.3 114.4 120.8 124.6 0.78 987 3,272 109.8 

6 years ................. 93.9 96.0 102.4 108.7 112.0 118.8 122.7 1.59 156 570 107.8 

7 years ................. 95.3 98.0 102.6 107.7 111.8 117.7 120.8 1.46 172 570 107.8 

8 years ................. 96.7 98.9 103.4 109.1 113.9 119.1 124.0 1.08 192 560 109.2 

9 years ................. 97.5 100.8 105.6 109.1 114.1 120.3 124.2 .92 158 534 110.1 

10 years ................ 97.1 101.6 105.3 110.1 116.7 121.3 124.4 .93 142 530 110.9 

11 years ................ 99.3 102.0 106.7 112.8 119.7 125.2 130.0 .98 167 507 113.3 

Boys, 6-11 years ...... 96.3 99.6 104.0 109.0 113.9 119.8 123.0 1.02 464 1,642 109.5 

6 years ................. 93.7 96.8 103.1 109.0 112.2 119.1 123.3 1.36 84 289 108.8 

7 years .......... :. ...... 96.6 98.1 102.6 106.7 111.3 116.8 119.3 1.75 79 286 107.4 

8 years ................. 98.9 99.8 103.6 109.7 113.9 116.9 121.2 1.18 79 279 109.2 

9 years ................. 97.0 101.2 105.3 108.2 112.4 120.9 126.0 1.10 74 269 109.9 

10 years ................ 96.2 101.8 104.6 109.6 116.6 120.7 121.3 1.11 65 264 110.1 

11 years ................ 96.3 100.2 105.3 111.1 116.3 121.8 125.7 1.59 83 255 111.5 

Girls, 6-11 years ...... 96.3 98.3 104.4 109.7 115.2 121.7 125.7 0.71 523 1,629 110.1 

6 years ................. 93.9 95.3 100.0 107.6 111.4 116.9 121.9 2.08 72 281 106.7 

7 years ................. 94.6 97.7 102.7 108.6 112.7 118.7 121.2 1.34 93 284 108.2 

8 years ................. 96.0 97.0 103.2 108.8 113.9 121.6 126.1 1.24 113 281 109.1 

9 years ................. 97.8 99.3 105.7 110.0 115.6 120.2 122.1 .82 84 265 110.4 

10 years ................ 98.2 101.5 106.6 111.2 116.9 123.6 127.7 1.03 77 266 111.6 

11 years ................ 101.0 104.8 108.0 114.6 121.2 127.6 131.9 1.67 84 253 115.1 

- -

NOTE: s5Oth = standard error of the median, n = sample size, N = estimated number of children in population in thousands, 

X = mean. 

17 
Table 2. Diastolic blood pressure of children by race, sex,and age at last birthday: Selected percentiles,standard error of the median, 

sample sizes,and mean, United States, 196355 

Percentile 

Race,sex,and age '50th n N 

5th 10th 25th 60th 75th 90th 95th 

- I 

All races mm.Hg 

Both sexes,6-11 years ........ 53.0 56.4 61.3 67.2 71.9 75.9 78.6 I 0.70 7,119 23,784 66.6 

-

6years ....................... 51.1 64.5 60.4 66.1 70.9 75.1 78.1 .81 1,111 4,098 65.5 

7years ....................... 52.9 56.1 60.9 66.6 70.9 75.1 77.3 .65 1,241 4,084 66.0 

8years ....................... 53.3 56.4 61.1 67.3 72.1 76.2 78.9 .92 1,231 3,986 66.8 

9years ....................... 53.7 56.9 62.2 68.0 72.3 76.3 78.7 .70 1,184 3,957 67.2 

IOyears ...................... 54.6 57.6 62.7 68.4 72.7 76.7 79.2 .72 1,160 3,867 67.6 

11 years ...................... 52.8 56.6 61.2 67.2 72.2 76.2 78.4 .76 1,192 3,792 66.8 

Boys,B-11 years ............ 52.9 56.6 61.1 67.0 71.4 75.6 78.2 0.72 3,632 12,081 66.4 

6years ....................... 51.9 55.7 60.6 66.2 70.4 74.2 76..9 .90 575 2,082 65.5 

7years ....................... 52.3 55.7 61.0 66.3 70.4 74.6 77.1 .77 632 2,074 65.7 

8years ....................... 53.7 57.0 61.2 66.9 71.9 76.1 79.3 .77 618 2,026 66.7 

9years ....................... 53.0 56.5 61.6 67.3 71.6 76.0 78.6 .66 2,012 66.7 

IOyears ...................... 54.6 57.2 61.7 68.3 72.6 76.3 78.8 1.06 576 1,963 67.2 

II years ...................... 52.7 56.6 61.0 67.6 71.8 76.0 78.1 .89 628 1,924 66.7 

Girls,6-11 years ............ 53.0 56.2 61.6 67.4 72.2 76.2 78.8 0.73 3,487 11,703 66.9 

6years ....................... 50.7 53.8 60.3 66.1 71.3 76.2 78.6 .85 536 2,016 65.5 

7years ....................... 53.6 56.3 60.8 66.7 71.1 75.6 77.7 .59 609 2,010 66.2 

8years ....................... 53.1 55.6 61.0 67.9 72.3 76.2 78.3 1.18 613 1,960 66.8 

9years ....................... 54.6 57.7 62.8 68.8 73.2 76.6 78.8 .79 581 1,945 67.7 

IOyears ...................... 54.6 58.2 63.8 68.5 72.9 77.3 79.7 57 584 1,904 68.1 

Ilyears ...................... 52.9 56.7 61.3 67.0 72.7 76.4 78.9 .73 564 1,868 66.9 

White 

Both sexes,6-11 years ........ 52.8 56.2 61.1 67.1 71.7 75.8 78.3 0.76 6,100 20,403 66.4 

6years ....................... 50.9 53.9 60.0 65.8 70.4 74.7 77.7 .90 950 3,509 65.1 

7years ....................... 53.2 56.0 60.8 66.3 70.8 74.9 77.1 .74 1,063 3,497 65.9 

8years ....................... 53.1 56.4 61.2 67.3 72.0 76.0 78.3 .95 1,035 3,413 66.7 

9years ....................... 53.2 56.7 62.1 67.9 72.3 m76.3 78.7 .75 1,019 3,393 67.1 

IOyears ...................... 54.8 57.7 62.7 68.2 72.4 76.3 79.2 .70 1,014 3,324 67.5 

Ilyears ...................... 52.7 56.3 61.1 67.0 71.9 75.9 78.2 .80 1,019 3,267 66.6 

Boys,6-11 years ............ 52.7 56.2 60.8 66.9 71.1 75.2 78.0 0.79 3,153 10,391 66.2 

6years ....................... 51.3 54.6 60.0 65.7 69.9 73.9 75.9 .91 489 1,787 65.0 

7years ....................... 52.7 55.5 60.8 66.1 70.3 74.3 76.8 .91 551 1,781 65.6 

8years ....................... 53.0 57.1 61.1 66.9 71.7 75.9 78.7 .95 537 1,739 66.6 

9years ....................... 52.2 56.1 61.0 67.2 71.6 75.8 78.2 .81 525 1.730 66.5 

IOyears ...................... 54.6 57.2 61.3 67.9 71.9 75.8 78.8 1.13 509 1,692 66.8 

Ilyears .- .................... 52.8 56.4 61.1 67.3 71.4 75.7 78.2 .99 542 1,662 66.6 

NOTE: s5Oth = standard error of the median, n = sample size,N = estimated number of children in population in thousands, 

X= mean. 

18 
Table 2. Diastolic blood pressure of children by race, sex, and age at last birthday: Selected percentiles, standard error of the median, 

sample sizes, and mean, United States, 1963-65-Con. 

Percentile 

Race, sex, and age ‘50th n N x 

5th 10th 25th 50th 75th 90th 95th 

White-Con. mm. Hg 

Girls, 6-11 years ............ 52.9 56.1 61.6 67.3 72.1 76.1 78.8 0.72 2,947 10,012 66.8 

6 years ....................... 50.5 53.0 60.0 65.9 71.2 76.2 78.6 1.09 461 1,722 65.3 

7 years ....................... 53.7 56.4 60.8 66.7 71.1 75.5 77.9 .64 512 1,716 66.2 

8 years ....................... 53.2 55.9 61.3 67.9 72.1 76.1 78.1 1.17 498 1,674 66.9 

9 years ....................... 53.9 57.4 62.9 68.7 73.2 76.7 79.0 -80 494 1,663 67.7 

10 years ...................... 55.2 58.7 64.0 68.4 72.9 77.3 79.7 -56 505 1,632 68.3 

11 years ...................... 52.3 56.3 61.1 66.6 72.3 76.1 78.4 .79 477 1,605 66.5 

Negro 

Both sexes, 6-11 years ........ 54.6 57.2 62.8 68.4 73.2 77.1 79.4 0.87 987 3,272 67.8 

6 years ....................... 55.8 58.8 63.6 67.9 72.2 77.3 79.3 1.18 156 570 68.1 

7 years ....................... 51.7 57.0 62.3 67.1 71.5 75.8 78.2 .65 172 570 66.7 

8 years ....................... 54.5 56.2 60.3 67.4 73.4 77.7 81.3 1.45 192 560 67.2 

9 years ....................... 56.7 58.9 63.8 68.8 73.0 76.6 78.9 .88 158 534 68.1 

10 years ...................... 53.7 56.2 62.7 69.3 74.6 77.7 79.7 1.69 142 530 68.3 

11 years ...................... 53.2 57.7 63.1 68.9 74.3 77.8 79.3 .86 167 507 68.3 

Boys, 6-11 years ............ 55.1 57.4 63.3 68.3 73.3 77.5 80.2 0.77 464 1,642 68.1 

6 years ....................... 57.5 59.9 64.3 68.6 73.2 78.1 80.0 .99 84 289 69.0 

7 years ....................... 50.2 57.8 62.9 67.1 71.1 75.8 86.6 .86 79 286 66.8 

8 years ....................... 56.0 56.9 62.8 67.0 73.2 78.6 82.3 1.61 79 279 67.8 

9 years ....................... 56.2 59.2 63.9 67.9 71.9 77.0 81 .O .74 74 269 67.9 

10 years ...................... 54.4 57.1 64.6 70.3 75.3 77.8 79.7 2.12 65 264 69.4 

11 years ...................... 51.7 56.8 60.2 68.7 74.0 77.0 78.1 1.38 83 255 67.7 

Girls, 6-I 1 years ............ 54.0 56.9 61.5 68.5 73.0 76.9 79.0 1.07 523 1,629 67.4 

6 years ........................ 55.8 58.0 62.0 67.1 71.6 76.7 78.8 1.33 72 281 67.2 

7 years ....................... 52.8 56.1 60.9 67.1 72.0 75.8 77.1 1.14 93 284 66.5 

8 years ....................... 51.0 54.8 59.2 68.3 73.6 77.7 80.7 2.82 113 281 66.6 

9 years ....................... 57.0 58.8 62.3 69.8 73.7 76.6 77.2 .70 84 265 68.3 

IO years ...................... 53.1 54.8 60.6 68.6 72.6 77.3 79.7 1.73 77 266 67.1 

11 years ...................... 56.3 59.0 64.3 69.3 74.7 78.7 80.0 .93 84 253 69.0 

NOTE: s5Oth = standard error of the median, n = sample size, N = estimated number of children in population in thousands, 

Z = mean. 

19 
Table 3. Median systolic and diastolic blood pressure in children aged 6-11 years by annual family income and race of child: United 

States, 1963-65 

Annual family income 

Race Less than $3,000-

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

White ............................................... 

Negro ............................................... 

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

White .............................. 

Negro ............................................... 

$10,000 

$3,000 $9,999 or more 

Median systolic blood pressure in mm, Hg 

109.3 109.5 109.2 

108.7 109.7 109.1 

110.3 108.2 110.6 

Median diastolic blood pressure in mm. Hg 

..= ............... 

Table 4. Median systolic and diastolic blood pressure in children aged 6-11 years by education of parent and race of child: United 

States, 1963-65 

Race 

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

White .................................................... 

Negro .................................................... 

Total ..,......................................... 

White ................................................ 

Negro ................................................ 

Education of parent 

Less than 13 years 

5 years 

5-8 years 9-I 2 wars or mOre 

Median systolic blood pressure in mm. Hg 

110.4 109.3 109.6 108.8 

110.6 109.2 109.7 108.8 

110.2 110.0 108.6 109.1 

Median diastolic blood pressure in mm. Hg 

. . . 

. . . 

. . . 

20 
APPENDIX 

SPECIAL SOURCES OF VARIATION 

IN THE MEASUREMENT 

Time of Examination 

In the HES survey of adults, it was observed 

that blood pressure measurements tended to be 

slightly higher in the afternoon than in the 

morning.’ Table I shows that this held true in 

children for systolic pressure, but not for diastolic pressure. As in the survey of adults, the 

magnitude of the morning-afternoon difference 

was small enough that it could be ignored in 

other analyses of these data. 

Comparisons among the morning or afternoon 

times were hindered in that the large majority of 

exams started at about the same time, 9-9:59 

a.m. and l-l :59 p.m. 

Order of Measurement 

The examinee’s first blood pressure determination was made before the physical exam; the 

second was made some time later, after the electrocardiogram. On the average, the first measurement was higher than the second, both for 

OF BLOOD PRESSURE 

systolic and for diastolic pressure (table II). The 

difference between the medians was 3.6 mm. Hg 

for systolic and 1.7 mm. Hg for diastolic and 

was of approximately the same magnitude for 

the higher and lower percentiles as well. In view 

of the effect of apprehension on blood pressure 

level, it was to be expected that measurements 

early in the course of the exam would be higher 

than later ones. A similar phenomenon was observed in the HES survey of adults.’ 

Examiner Variability 

The blood pressure measurements in this survey were obtained by four nurses. In general, 

only one was assigned to work at any particular 

location of the examining caravan. The percent 

distribution of examinees by age, sex, race, and 

examining nurse is shown in table III. Among 

the nurses there were small differences in the 

distribution of examinees by age and sex and 

larger differences by race. The median systolic 

Table I. Median blood pressure and number of examinees by beginning time of examination 

Median blood pressure and 

number of examinees 

Systolic pressure (mm. Hg) . . . . . . . . . . . . . 

Diastolic pressure (mm. Hg) . . . . . _ . . . _ . . 

21 
Table II. Blood pressure of children by order of measurement, and diastolic blood pressure of the children 

selected percentilesa examined at those locations where each nurse 

worked are shown in table IV. The values have 

been adjusted to account for differences in the 

Blood pressure age, sex, and race composition of the examinees

(mm. Hg) in the four groups. For the purpose of this 

analysis, values for examinees at locations where 

Systolic I , . . . . . 100.0 104.4 111.6 117,8 123.8 more than one nurse was employed have been Systolic II . . , . . 97.9 102.1 108.0 113.8 120.0 excluded. 

Diastolic I . . . . . 56.2 61.6 68.0 72.4 78.0 The differences in the median systolic blood 

Diastolic II . . . . . 55.5 60.0 66.3 70.6 75.9 pressure obtained by each nurse were relatively 

small, the largest being 2.8 mm. Hg. Diastolic 

aSample weights are not taken into account in this table; the pressure variation between them, however, was

figures presented do not represent estimates for the U.S. greater; the largest difference was 8.8 mm. Hg. population. The fact that diastolic pressure was measured 

Table I I I. Number and percent distribution of examinees by age, sex, race, and examining nurse 

Examining nurse 

Age, sex, and race of examinees 

1 I 2 I 3 I 4 

Number 

Total examineesa . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1,465 1 2,960 1 732 1 1,123 

Percent distribution 

Age 

6-11 years . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100.0 100.0 100.0 100.1 

6-7years.. ........................................ 33.0 32.9 32.9 32.7 

B-9years .......................................... 34.1 33.6 32.7 35.4 

IO-I 1 years ......................................... 32.9 33.5 34.4 32.0 k 

Sex -

Both sexes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100.0 100.0 100.0 100.0 

Male ............................................. 50.6 52.3 49.2 50.4 

Female ........................................... 49.4 47.7 50.8 49.6 

Race 

Total......................:................. 100.0 100.0 100.0 100.0 

-

White . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79..8 89.7 94.8 84.8 

Negro . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20.2 10.3 5.2 15.2 

aExcludes 839 children who were examined at locations where there was more than 1 examining nurse. 

22 
Table IV. Number of examinees and median systolic and diastolic blood pressure of children by examining nursea 

Examining nurse 

Median blood pressure and number of examinees 

1 2 3 4 

Total examineesb . . . . . . . . . , . . . . . . . . . . . . . . . . . . . . . . 1,465 2,960 732 1,123 

Systolic blood pressure (mm. HgP . . . . . . . . . . . . . . . . . . . . . . . . . 110.2 108.4 111.2 110.4 

Diastolic blood pressure (mm. Hg)c . . . . . . . . . . . . . . . . . . . . . . . . 60.5 69.3 64.9 66.6 

aSample weights are not taken into account in this table; the figures presented do not represent estimates for the U.S. population. 

bExcludes 839 children who were examined at locations where 

‘Adjusted to the racial distribution of all examinees. 

less unformly than systolic pressure is not surprising since the end point for diastohc (disappearance of sounds) is usually less clear cut than 

that for systolic (initiation of sounds) and would 

be more susceptible to differences in the auditory thresholds of the nurses. 

This discrepancy among the nurses in the 

measurement of diastolic blood pressure has not 

affected the analysis of diastolic pressure variation by age or sex since each of the four nurses 

examined about the same proportion of children 

in the various age and sex groups (table III). It 

has affected the diastolic pressure difference between the races by understating the difference. 

Nurse 1, who, of the four nurses, measured the 

highest percentage of Negro children, tended to 

measure diastolic pressure lower than the others. 

Thus, since the Negro chiIdren were observed as 

having a higher diastolic pressure, if the variability among nurses had been taken into account, the difference between Negro and white 

children would have been slightly greater still. 

Subsequent reports concerning the relationship of diastolic blood pressure and some other 

characteristic, if each of the nurses has not examined the same proportion of persons with this 

characteristic, wiII have to take these examiner 

differences into account. 

End-Digit Preference 

Table V shows the distribution of the final 

digit of the first and second blood pressure 

measurements and of the average of the two 

measurements. Despite instructions to record 

blood pressure to the nearest 2 m m. Hg, the 

nurses recorded several odd end digits. Among 

there was more than one examining nurse. 

the even digits there was more variation than 

would have been expected by chance, with “0” 

recorded the most frequently, “6” the least. 

This digit preference was far less, however, than 

that shown by the physicians who measured 

blood pressure in the HES survey of adults.’ 

Once the two measurements were averaged, the 

digit preference was obscured (table V). 

Parameter and Variance Estimation 

All estimates of parameters presented in this 

report are weighted estimates, taking into account the statistical weights that were assigned 

to each of the 7,119 examined children so that 

they might very closely represent the 6-l l-yearold noninstitutionalized population of the 

United States in 1963-65. Because of the complex design of the HES, which has been described eIsewhere,* a half-sample replication 

technique’ 6 deveIoped by the U.S. Bureau of 

the Census was used to produce variance estimates for sample statistics. These estimates are 

based on 20 balanced half-samples created by 

orthogonally selecting one from each of the 20 

pairs of primary sampling units employed in the 

HES. The desired statistic is calculated for each 

half-sample &d for the total sample. The variance (in this report, the variance of distribution 

of medians of the half-samples) is then computed by the usual mean-squared deviation formula (with 20 degrees of freedom), and the 

standard error is simply the square root of this 

value. This approach compensates for the effects 

of clustering, stratification, ratio estimation, and 

poststratification, all of which are part of the 

sampling procedure of the HES. 

23 
Table V. Distribution of end digits on blood pressure measurement by order of measurement 

Avg. Avg. 

End digit Systolic Diastolic systolic diastolic Avg. Avg. 

I II 

II II systolic diastolic 

0 .......................................... 

1 .......................................... 

2 .......................................... 

3 .......................................... 

4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

. 5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

6 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

7 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 .......................................... 

Missing ...................................... 

1,759 1,756 

1,442 1,319 

2 

1,534 1,216 

6 5 

1,047 954 

1 1 

1,321 1,860 

3 

6 6 

Number of examinees 

1,724 1,856 772 897 

3 2 749 712 

1,375 1,240 8T5 630 

3 12 695 646 

1,490 1,212 630 671 

9 9 697 667 

1,071 1,049 679 656 

2 13 685 708 

1,405 1;705 658 688 

10 3 736 821 

17 18 3 3 

* U. S. GOVERNh03NT PRINTING OFFICE : 1914 543-881/a 

24 
VITAL AND HEALTH STATISTICS PUBLICATION SERIES 

Formerly U.S. Public Health Service Publication No. 1000 

Series 1. Programs and collection procedures.-Reports whichdescribe thegeneralprograms of the National 

Center for Health Statistics and its offices anddivisions, data collection methods used, definitions, 

and other material necessary for understanding the data. 

Series 2. Data evaluation and methods research.- Studies of new statistical methodology including: experimental tests of new survey methods, studies of vital statistics collection methods, new analytical 

techniques, objective evaluations of reliability of collected data, contributions to statistical theory. 

Series 3. Analytical studies. -Reports presenting analytical or interpretive studies basedon vital and health 

statistics, carrying the analysis further than the expository types of reports in the other series. 

Series 4. Documents and committee reports.- Final reports of major committees concerned with vital and 

health statistics, and documents such as recommended model vital registration laws and revised 

birth and death certificates. 

Series 10. Data from the Health ICerview Survev.-Statistics on illness, accidental injuries, disabilitv, use 

of hospital, medical, dental, and other services, and other health-related topics, based on data 

collected in a continuing national household interview survey. 

Series 11. Data from the Health Examination Survey. -Data from direct examinatiou, testing, and measurement of national samples of the civilian, noninstitutional population provide the basis for LWOtypes 

of reports: (1) estimates of the medically defined prevalence of specific diseases in the United 

States and the distributions of the population with respect to physical, physiological, and psychological characteristics; and (2) analysis of relationships among the various measurements without 

reference to an explicit finite universe of persons. 

Series 12. Data from the Institutional Population Surveys .- Statistics relating to the health characteristics of 

persons in institutions, and their medical, nursing, and personal care received, based on national 

samples of establishments providing these services and samples of the residents or patients. 

Series 13. Data from the Hospital Discharge Survey. -Statistics relating to discharged patients in short-stay 

hospitals, based on a sample of patient records in a national sample of hospitals, 

Series 14. Data on health resources: manpower and facilities. -Statistics on the numbers, geographic distribution, and characteristics of health resources including physicians, dentists, nurses, other health 

occupations, hospitals, nursing homes, and outpatient facilities. 

Series 20. Data on mortality. -Various statistics on mortality other than as included in regular annual or 

monthly reports- special analyses by cause of death, age, and other demographic variables, also 

geographic and time series analyses. 

Series 21. Data on natality, marriage, and divorce.- Various statistics on natal@, marriage, and divorce 

other than as included in regular annual or monthly reports--special analyses by demographic 

variables, also geographic and time series analyses, studies of fertility. 

Series 22. Data from the National Natality and Mortality Surveys.-Statistics on characteristics of births 

and deaths not available from the vital records, based on sample surveys stemming from these 

records, including such topics as mortality by socioeconomic class, hospital experience in the 

last year of life, medical care during pregnancy, health insurance coverage, etc. 

For a list of titles of reports published in these series, write to: Office of Information 

National Center for Health Statistics 

Public Health Service, HRA 

Rockville, Md. 20852