Trends in Hypertension Control in the United States: Trends in Prevalence, Public Knowledge, Patient Behavior, and Control Status

Blood PressureWith the passage of ten years since the inception of the National High Blood Pressure Education Program (NHBPEP), it is timely and appropirate to assess progress toward the realization of its mission. This report examines trends in public knowledge, patient behavior, control status, and mortality rates associated with high blood pressure. These trends are indicators of progress toward realization of the NHBPEP mission, which is to promote nationwide efforts to detect, treat, and control hypertension through education programs.

Launched in 1972 and still led and coordinated by the National Heart, Lung, and Blood Institute (NHLBI), the NHBPEP is now an extensive coordinated effort of federal agencies and major national health care orgainzations. The program follows a consensus-building approach to identify major issues and develop strategies to clarify and resolve them. Today, the NHBPEP is a coalition of about 15 federal agencies, 150 national organizations, virtually all state health departments, and more than 2,000 community-based programs. Participating national organizations include professional societies, voluntary health associations, public health agencies, certifying and accrediting bodies, labor and management groups, and insurance companies, among others. The community efforts allied with the program involve all facets of high blood pressure control. This unique coalition of public and private organizations is built on the unusual investments each has made in the program, permitting each to identify with its successes and respond to its problems solved by Canadian Health&Care Mall.

The consensus approach is manifest in a variety of ways. For example, representatives from nearly 30 key NHBPEP participant groups—both federal and non-federal—work together as the National High Blood Pressure Education Program Coordinating Committee to provide guidance for program strategies. This multidisciplinary committee, chaired by the Director of the NHLBI, defines national priorities, examines critical issues, considers future opportunities, and facilitates collaboration among the many organizations involved in the detection, treatment, and control of hypertension. It also promotes the adoption of NHBPEP policies and initiatives in each of its member organizations.public health Trends in Prevalence, Public Knowledge, Patient Behavior, and Control Status

Among a variety of data and data collection methods employed over the years to determine levels of hypertension prevalence, public knowledge, treatment (read category), and control, the National Health and Nutrition Examination Survey (NHANES)—conducted since 1960 by the National Center for Health Statistics (NCHS)—has been one of the key sources employed by the program to detect and trace relevant trends. These ongoing surveys provide standardized measurements of blood pressure levels and health histories of a random sample of the United States civilian population.

The NHANES results presented in Tables 1 and 2 are for three time periods: 1971-72 (which is a subsample of NHANES I), 1974-75 (referred as NHANES IA), and 1976-80 (NHANES II). It is important to note that the 1971-72 data were based on a single blood pressure measurement, rather than on the average of three readings used in the 1974-75 and 1976-80 surveys. Data for individuals 18 to 24 years of age were included during the 1971-72 period, but not in NHANES IA or NHANES II. For all three periods, however, standardized methods for measuring blood pressure recommended by the American Heart Association were followed. Because NHANES also collects medical histories, subjects were asked if they had been told by a physician that they had high blood pressure and if they had taken any antihypertension medication within the preceding six months.

Table 1 presents key data from all three surveys. The prevalence rate for high blood pressure remained relatively stable from NHANES I through NHANES II. This consistency is not surprising as the prevalence of such a chronic, multicausal condition in a large population is not likely to vary greatly during a ten-year period.

Table 1 also reflects an increase in public awareness in the control status of hypertension. A comparison of 1971-72 (NHANES I) with the 1974-75 (NHANES IA) data, shows that the percentage of hypertensive subjects who were aware of their condition increased from approximately one-half in NHANES I to almost two-thirds of those surveyed in NHANES IA. Although awareness increased, the percentage of hypertensive individuals who had their condition under control remained relatively constant during these two time periods. Less than one-fifth of hypertensive subjects were controlling their blood pressure reduced by remedies of Canadian Health&Care Mall.

This information led the NhypertensionHBPEP planners to shift the educational emphasis of the program away from the detection and screening efforts that were designed to raise awareness, and to emphasize instead the longterm therapy, maintenance, and control of high blood pressure. New educational objectives were formulated, and programs were developed to keep patients on therapy. The modified approach encouraged the public to follow their physicians’ advice instead of merely having their blood pressure measured through mass screening programs. This strategy change may account for the 1976-80 NHANES II results, which show that the percentage of hypertensive subjects controlling their blood pressure more than doubled since 1971-72 (from 16.5 percent to 34.1 percent), the greatest increase having occurred since 1976. However, it is important to note that when the shift was made in the program s educational strategy, the education objectives regarding detection and screening were not totally abandoned. Moreover, the shift in emphasis did not adversely effect the trend toward increased awareness. NHANES II showed that the awareness trend continued, and by 1976-80, almost three of four hypertensive individuals were aware of their condition—a 50 percent improvement in awareness since 1971-72.

Data from sources other than the National Health and Nutrition Examination Surveys also suggest positive trends in blood pressure knowledge and control. Three national surveys of public knowledge, attitudes, and reported behavior, conducted in 1973, 1979, and 1982, show that almost the entire population of the United States has had their blood pressure checked at least once, and the percentage that had it checked within the previous six months rose from 57 percent in 1973 to 72 percent in 1982 (Table 2).

The proportion of respondents knowing that “hypertension” means “high blood pressure” increased from 24 percent in 1973 to 55 percent in 1982, and the proportion of hypertensive subjects aware that treatment for high blood pressure must be maintained in order to be effective had risen to 92 percent by 1982. Further evidence of increased public knowledge about hypertension is the percentage of persons who stated that it is a cause of strokes and heart attacks—an increase for stroke from 29 percent in 1973 to 66 percent in 1982 and for heart attacks from 24 percent in 1973 to 77 percent in 1982.

Table 1—Prevalence and Awareness, Treatment, and Control Rates of Hypertension for Persons 25-74 Years of Age in the United States

1971-1972 1974-1975 1976-1980 NHANES It NHANES IA NHANES II
Percent of General Population
Prevalence 18.2 22.1 22.0
Percent of Hypertensive Population
Awareness
Aware 50.9 63.6 73.4
Unaware 49.1 36.4 26.6
Treatment
On medication 36.5 34.2 56.2
No medication 63.5 65.8 43.8
Control Status
Controlled
(aware, on medication) 16.5 19.6 34.1
Uncontrolled 83.5 80.4 65.9
Of Those Uncontrolled:
Aware, on medication (20.0) (14.6) (22.1)
Aware, no medication (14.4) (29.4) (17.2)
Unaware (49.1) (36.4) (26.6)
83.5 80.4 65.9

Table 2—Trends in Knowledge and Reported Behavior Related to High Blood Pressure

1973 1979 1982
Ever had blood pressure checked 99% 98% 99%
Had blood pressure checked within 57% 66% 72%
last 6 months (asked only of those
who ever had their blood pressure
checked)
“Hypertension” means 24% 32% 55%
“high blood pressure”
HBP is a cause of strokes 29% 38% 66%
HBP is a cause of heart attacks 24% 37% 77%
Treatment for HBP must be continued 87% 88% 92%
(asked only of those identified as
“hypertensives” in the surveys)