TRENDS IN THE PREVALENCE, AWARENESS, TREATMENT, AND CONTROL OF HYPERTENSION IN THE ADULT US POPULATION - DATA FROM THE HEALTH EXAMINATION SURVEYS, 1960 TO 1991
Vl. Burt et al., TRENDS IN THE PREVALENCE, AWARENESS, TREATMENT, AND CONTROL OF HYPERTENSION IN THE ADULT US POPULATION - DATA FROM THE HEALTH EXAMINATION SURVEYS, 1960 TO 1991, Hypertension, 26(1), 1995, pp. 60-69
The objective of this study was to describe secular trends in the dist
ribution of blood pressure and prevalence of hypertension in US adults
and changes in rates of awareness, treatment, and control of hyperten
sion. The study design comprised nationally representative cross-secti
onal surveys with both an in-person interview and a medical examinatio
n that included blood pressure measurement. Between 6530 and 13 645 ad
ults, aged 18 through 74 years, were examined in each of four separate
national surveys during 1960-1962, 1971-1974, 1976-1980, and 1985-199
1. Protocols for blood pressure measurement varied significantly acros
s the surveys and are presented in detail. Between the first (1971-197
4) and second (1976-1980) National Health and Nutrition Examination Su
rveys (NHANES I and NHANES II, respectively), age-adjusted prevalence
of hypertension at greater than or equal to 160/95 mm Hg remained stab
le at approximately 20%. In NHANES III (1988-1991), it was 14.2%. Age-
adjusted prevalence at greater than or equal to 140/90 mm Hg peaked at
36.3% in NHANES I and declined to 20.4% in NHANES III. Age-specific p
revalence rates have decreased for every age-sex-race subgroup except
for black men aged 50 and older. Age-adjusted mean systolic pressures
declined progressively from 131 mm Hg at the NHANES I examination to 1
19 mm Hg at the NHANES III examination. The mean systolic and diastoli
c pressures of every sex-race subgroup declined between NHANES II and
III (3 to 6 mm Hg systolic, 6 to 9 mm Hg diastolic). During the interv
al between NHANES II and III, the threshold for defining hypertension
was changed from 160/95 to 140/90 mm Hg. Hypertension awareness has in
creased substantially at both thresholds, to 89% and 73% for 160/1995
and 140/90 mm Hg, respectively. Compared with only 16% of all people w
ith hypertension being <160/95 mm Hg in 1960-1962 and 1971-1974, 64% o
f all people with hypertension now have it controlled to below the 160
/95 mm Hg threshold but only 29% to below 140/90 mm Hg. For people wit
h treated hypertension, the rate of control (<140/90 mm Hg) ranges fro
m 47% of black men to 60% of white women. Hypertension prevalence in t
he United States has declined progressively since 1971, and the distri
butions of systolic and diastolic pressures have shifted downward duri
ng the approximately 30-year period between 1960-1962 and 1988-1991. V
ariation in blood pressure measurement techniques may explain some of
the decline in prevalence and the downward shift in distribution. Hype
rtension awareness, treatment, and control also have improved tremendo
usly during the same period, accounting for much of the shift at the u
pper end of the distribution. Despite these favorable trends, many peo
ple with hypertension are unaware of their condition, and many more ar
e untreated or inadequately treated.