Perspectives in Disease Prevention and Health Promotion High Blood Pressure Control Project -- South Carolina, 1978-1982
With the recognition that efforts to assess high blood pressure were needed at the community level, the National Heart, Lung, and Blood Institute allocated funds for state-based programs to document the prevalence of high blood pressure, to design and implement intervention strategies, and to evaluate the impact of state-level planning and coordination on the control of high blood pressure. South Carolina was one of seven states* selected to participate, and in October 1977, funding was awarded to the South Carolina Department of Health and Environmental Control (DHEC) to establish the High Blood Pressure Control Project (SCHBPCP).
With the University of South Carolina School of Public Health, the Carolina Health Survey was conducted in 1979 and 1982 to determine the prevalence of high blood pressure and the status of awareness, treatment, and control levels among the hypertensive population. The baseline (1979) and follow-up (1982) surveys were statewide household surveys using multistage probability sampling plans (1-3) based on U.S. census data. Approximately 5,300 adults (18 years of age or older) were interviewed in the baseline survey, with 5,200 participating in the follow-up survey. To make projections for the entire state, a weighting procedure was used to adjust for sample selection probabilities and nonresponses within age/race/sex subgroups.
Hypertension-related mortality was examined through analysis of annual death certificate data maintained by DHEC's Office of Vital Records and Public Health Statistics. This information provided a baseline assessment of mortality and allowed monitoring of selected causes of death to detect changes during the SCHBPCP. Hypertension-related morbidity was examined through use of hospital discharge data provided by the Office of Cooperative Health Statistics, Division of Research and Statistical Services, South Carolina Budget and Control Board. These data were also used in baseline needs assessment and for monitoring changes in hospitalizations for selected disease categories.
From the baseline Carolina Health Survey, it is projected that 35% of adult South Carolinians had high blood pressure in 1979. Although this number declined slightly in the 1982 follow-up survey, with a projected 31% of persons identified as having high blood pressure, this difference was not statistically significant. Survey respondents were considered to have high blood pressure if they had a blood pressure reading of 140/90 or higher (average of three readings, taken at 5-minute intervals) or if they reported they were taking antihypertensive medication.
Both baseline and follow-up surveys indicated that 99% of all adults have had their blood pressures taken at some time. Most had their blood pressures taken by doctors or nurses, but this changed from 94% at baseline to 88% at follow-up. This shift may indicate individuals taking greater responsibility for their own blood pressure measurement, as well as an increase in the number of people participating in community blood pressure screenings.
For those reporting histories of high blood pressure at baseline, 59% reported having seen a doctor about their blood pressures within the previous 6 months, compared to 58% at follow-up. Of this group, at baseline, 77% had antihypertensive medication prescribed, and 56% were taking that medication; at follow-up, 74% had medication prescribed, and 74% were currently using it. Among those who had discontinued their antihypertensive medication, the most common reasons in both surveys were: their doctors had advised them to stop; they no longer had high blood pressure; they no longer needed to take medication; they had undesirable side effects; or medication was too expensive.
Between baseline and follow-up, the proportion of hypertensives characterized as unaware of their conditions decreased 23%; this was accompanied by a 57% increase in the proportion of hypertensives characterized as aware, treated, and controlled. There was very little change in the proportion of hypertensives who are aware of their conditions, either treated or untreated, but uncontrolled.
At baseline, approximately 22% of respondents scored 80% or higher on the hypertension knowledge test; this proportion increased to 28% at follow-up. In both surveys, aware and treated hypertensives (whether or not controlled) were consistently more knowledgeable than normotensives, unaware hypertensives, and aware/untreated hypertensives.
Selected causes of hypertension-related deaths were monitored for possible changes during the SCHBPCP. However, because of the time lag in obtaining death certificate data, only 3 years' data (1979-1981) are available for comparison to the baseline period (1970-1978) before the inception of the project. For example, stroke mortality among all race/sex groups has been decreasing since 1970. This decline continued through 1979-1981, although no significant changes in rates were observed.
Changes in stroke mortality or other hypertension-related mortality were not expected to be detected in a brief 3-year time period. It is, however, expected that improvements in high blood pressure control will result in mortality changes that will be evident in later years.
Essential hypertension, cerebrovascular disease, and myocardial infarction were selected as the disease categories to be monitored through the Statewide Hospital Discharge Data System. Hospital discharge rates for all three of these conditions increased from 1978 to 1981. These changes may be related to a variety of contributing factors, such as improvements in medical/surgical procedures, emergency medical care, transportation, disease identification, and coding procedures. There may also be greater numbers of hospitalizations for diagnoses of hypertension-related diseases; improved containment of these conditions may prevent mortality but may require hospitalization for treatment.
While the increased number of hospitalizations for hypertension-related diseases was unexpected, it was accompanied by parallel increases in the number of total hospital discharges in the state. For example, in 1978, cerebrovascular disease represented 1.3% of the total discharges; in 1981, this proportion had increased by 1.8%. Similar increases were observed for the other related disease categories.
From the data presented, it appears that some positive changes have occurred in the control of high blood pressure in South Carolina since 1978. Although this assessment cannot document the specific causal relationships effecting these changes, it is possible to describe needs, develop intervention-targeted strategies, and assess subsequent change by using a systematic approach through which objective data are collected, analyzed, and evaluated.
Editorial Note: High blood pressure is one of the most prevalent chronic conditions affecting U.S. citizens (4). It is a major risk factor for cardiovascular disease (including cerebrovascular disease) and renal disease (5,6). In South Carolina, mortality rates for high blood pressure-related diseases are significantly higher than those reported in other states (7).
The DHEC has had state funding for high blood pressure screening, education, and follow-up services since 1973. South Carolina was the second state, following Georgia, to designate state funding for high blood pressure control activities. To augment these efforts, in 1976 federal funds became available for expansion of community-based services.
While the SCHBPCP was involved in documenting the status of high blood pressure control in South Carolina since 1978, it must be acknowledged that the control of high blood pressure is a complex process. Positive improvements may have occurred, but direct cause-and-effect relationships cannot be attributed solely to the SCHBPCP. However, the project did establish a comprehensive network of public, private, professional, and voluntary groups involved in blood pressure control activities, including screening and follow-up services, as well as public, patient, and professional education. A complete description of the programmatic aspects of the project is available from the Special Projects Section, Division of Chronic Disease, South Carolina DHEC, 2600 Bull Street, Columbia, South Carolina 29201. Reported in Preventive Medicine Quarterly 1984;8 (Summer):8-11, by DM Shepard, MAT, South Carolina Dept of Health and Environmental Control, Aiken, FC Wheeler, PhD, Special Projects Section, Div of Chronic Disease, South Carolina Dept of Health and Environmental Control, MC Weinrich, PhD, Dept of Epidemiology, School of Public Health, University of South Carolina, Columbia, E Devlin, project coordinator, staff and members, South Carolina Medical Association, South Carolina Affiliate, American Heart Association.
Disclaimer All MMWR HTML documents published before January 1993 are electronic conversions from ASCII text into HTML. This conversion may have resulted in character translation or format errors in the HTML version. Users should not rely on this HTML document, but are referred to the original MMWR paper copy for the official text, figures, and tables. An original paper copy of this issue can be obtained from the Superintendent of Documents, U.S. Government Printing Office (GPO), Washington, DC 20402-9371; telephone: (202) 512-1800. Contact GPO for current prices.**Questions or messages regarding errors in formatting should be addressed to email@example.com.
Page converted: 08/05/98
This page last reviewed 5/2/01