The impact of selected indices of antihypertensive treatment on all-cause mortality.

Two important questions regarding the results of the Hypertension Detection and Follow-up Program are: 1) how much of the difference in mortality between stepped care and referred care can be attributed to treatment for hypertension, and 2) was there a relationship between treatment of hypertension in the program and the risk of subsequent mortality of the participants? Neither of these questions can be answered within the original randomization scheme of the Hypertension Detection and Follow-up Program; however, statistical techniques can address these two questions. Crude analyses of blood pressures of survivors and deaths in each year of follow-up indicate that survivors had lower blood pressure than persons dying during the interval. An analysis using life table regression with time-dependent covariates suggests that well over half of the excess risk in the referred care group can be attributed to differences in factors related to hypertension treatment. Simultaneously testing the coefficients of the time-dependent variables (diastolic and systolic pressures, blood pressure goal, and medication status) suggests a highly significant relationship between these variables and the risk of subsequent mortality.