Persistence of reduction in blood pressure and mortality of participants in the Hypertension Detection and Follow-up Program. Hypertension Detection and Follow-up Program Cooperative Group

Abstract

The Hypertension Detection and Follow-up Program (HDFP) previously described a significant reduction in five-year, all-cause mortality in its intensively treated stepped care (SC) group relative to its referred care (RC) control group. At the time this finding was described, a proportion of the SC cohort had been treated for periods as long as 6.7 years, but comparable RC and SC mortality data beyond five years were not available. These data, which are described herein, indicate that the 6.7-year life-table mortality rates were 95.1/1000 participants for SC vs 116.3/1000 participants for RC, a larger mortality difference than was observed at five years. This favorable finding for SC extended to all major subgroups, including white women and those aged 30 to 49 years at trial entry. Six months after the close of the treatment trial, a two-year posttrial surveillance study, which extended mortality follow-up to 8.3 years, was conducted. The posttrial use of antihypertensive medication declined in SC and increased in RC participants so that by the end of the posttrial period, there was little difference in the percentages of SC and RC participants taking medication. Control of blood pressure, indicated by mean diastolic blood pressure and by percent of participants with a pressure of 90 mm Hg or less, was slightly better for SC than for RC participants (SC group, 86.5 mm Hg and 68% controlled; RC group, 87.8 mm Hg and 62% controlled). The absolute mortality advantage found at 6.7 years persisted and increased throughout the posttrial period of follow-up despite discontinuation of the formal SC therapy program. It is postulated that regression of hypertensive end-organ changes brought about by the more effective SC treatment caused this favorable outcome.