Temporal Patterns of Antihypertensive Medication Use Among Elderly Patients

OBJECTIVES: To estimate the incidence of newly treated hypertension and to describe the patterns of antihypertensive medication use among those aged 65 years and older. DESIGN: Medicare eligibility lists from four US communities (Forsyth County, North Carolina; Washington County, Maryland; Sacramento County, California; and Pittsburgh, Pa) were used to obtain a representative sample of 5201 community-dwelling elderly for the Cardiovascular Health Study, a prospective cohort study of risk factors for coronary heart disease and stroke. Participants were examined at baseline and again 1 year later. The two examinations included standardized questionnaires, blood pressure measurements, and the assessment of medication use by medication inventory. In this cohort analysis, we excluded 231 subjects (4.4%) who did not return for follow-up, 69 (1.3%) who had missing data for medications, and another 495 (9.5%) who were taking "antihypertensive" medications for an indication other than high blood pressure. INTERVENTIONS: None. RESULTS: Among the 4406 participants, 1613 used antihypertensive medications at both visits. Between the two visits, 144 started and 115 stopped antihypertensive therapy. Among nonusers at baseline, the annual incidence of newly treated hypertension was 5.2% in women and 5.6% in men. Due to the number of participants who stopped therapy, the overall prevalence of antihypertensive treatment increased only slightly, from 40.7% to 41.1% in women and from 37.1% to 38.2% in men, during 1 year of follow-up. After adjustment for age, systolic blood pressure, number of antihypertensive drugs, diabetes, and cardiovascular disease, the newly treated hypertensives were about half as likely as the previously treated hypertensives to receive diuretics (odds ratio OR, 0.59; P = .008) or beta-blockers (OR, 0.52; P = .01); and they were about twice as likely to receive calcium channel blockers (OR, 1.88; P < .004) or angiotensin converting enzyme inhibitors (OR, 2.40; P < .001). A similar pattern of within-person changes over time was apparent among the continuous users. CONCLUSIONS: Between June 1990 and June 1991, physicians were increasingly prescribing angiotensin converting enzyme inhibitors and calcium channel blockers in place of diuretics and beta-blockers for the treatment of hypertension in elderly patients, especially for those just starting therapy.