Trends in the prevalence and treatment of hypertension in Halifax County from 1985 to 1995

Background: The objective of this study was to document changes in the prev alence and treatment of hypertension in Halifax County from 1985 to 1995 in an effort to observe, at the population level, the consequences of the ava ilability of new antihypertensive medications. Methods: The study population comprised a random sample of Halifax County r esidents, aged 25-64 years, who responded to the 1985 and 1995 surveys of t he Halifax County MONICA Project and residents who responded to the Nova Sc otia Health Survey conducted in 1995. Data from the two 1995 surveys were p ooled. Information on hypertension awareness and use of medication were obt ained through questionnaires, and blood pressure was measured according to a standard protocol, using phase I and V of Korotkoff sounds as respective markers for systolic and diastolic pressures. Uncontrolled hypertension was defined as a systolic pressure of 140 mm Hg or greater and a diastolic pre ssure of 90 mm Hg or greater. Changes in the prevalence of hypertension, pr escribing trends and medication costs were examined, and the association be tween the type of anti- j hypertensive treatment and characteristics of the respondents with self-reported hypertension was investigated by multivaria te logistic regression. Results: Of the 917 people interviewed in 1985 and the 1338 in 1995, 274 (2 9.9%) and 356 (26.6%), respectively; reported a history of hypertension. Wh en age was controlled for, the proportion of respondents reporting hyperten sion did not differ between survey years or between men and women. The prop ortion of treated respondents who had uncontrolled hypertension increased b etween 1985 and 1995, from 32.6% to 57.4% among men and from 38.0% to 42.6% among women. An increase was seen in the use of calcium-channel blockers ( from 2.1% to 19.7%) and angiotensin-converting-enzyme inhibitors (from 5.2% to 25.4%); the proportion of patients receiving combination therapy or diu retics decreased (from 39.6% to 15.6% and from 31.3% to 17.2% respectively) . These changes were associated with an increase in the average daily cost of medication from $0.48 to $0.85 per patient. Interpretation: The shift to new antihypertensive drugs was not-associated with improved blood pressure control, but it was associated with an increas e in average medication rests per patient. Uncontrolled hypertension remain s a public health problem.