Antihypertensive drug therapy and survival by treatment status in a national survey.

The National Health and Nutrition Examination Survey (NHANES I) Epidemiologic Follow-up Study, an investigation of a cohort originally examined during the period 1971-1975, provided an opportunity to assess the frequency of antihypertensive drug therapy in the United States during the period 1982-1984. For most age-sex-race subgroups, the frequency of medication use during 1982-1984 was higher than that observed during 1976-1980 based on the NHANES II. In the interval 1982-1984, diuretic agents were the most frequent medications prescribed (47% of drugs prescribed), and beta-blockers were second (17%). At the time of the initial survey in 1971-1975, participants had their blood pressures measured and a history of diagnosis and treatment of hypertension ascertained. Follow-up for vital status was 93% complete by 1984 (average length of follow-up, 9 years). In white men and women aged 50 years and older, the relative risk of death increased steadily, from those with elevated blood pressure (systolic blood pressure greater than or equal to 160 mm Hg or diastolic blood pressure greater than or equal to 95 mm Hg) but no history of hypertension to those treated for hypertension but whose blood pressure was still elevated. Regardless of history or treatment, those with an elevated blood pressure had about a 25-30% excess risk of death. Evidence from these national studies shows a high frequency of antihypertensive drug therapy in 1982-1984 and suggests the importance of adequate blood pressure control for optimal survival.