Prognostic factors in the treatment of mild hypertension. The Management Committee of the Australian National Blood Pressure Study.

In the Australian therapeutic trial in patients with mild diastolic hypertension, univariate analysis of possible prognostic characteristics (covariates) at the time of entry into the study showed a higher incidence of trial end points, mainly events due to ischemic heart disease and cerebrovascular disease, in older subjects, men, cigarette smokers, and those with higher systolic blood pressures and lower body mass indexes than in their complementary groups. There was a lower incidence of these events in actively treated subjects than in control subjects at both high and low levels of incidence of each covariate considered, but treatment benefit was most marked in those with lower serum cholesterol levels and lower systolic blood pressures. Multivariate regression analyses of data from men and women separately, performed with the Cox proportional-hazards model, confirmed that the incidence of trial end points increased with age and with systolic blood pressure, and showed higher rates in cigarette smokers, which increased markedly with decreasing body weight. With respect to the effects of treatment, the multivariate analysis showed an increasing benefit with decreasing body weight in smokers. The apparent relationship of treatment benefit to systolic blood pressure in the univariate analysis did not reach statistical significance in the multivariate analysis. The greater benefit from treatment related to lower levels of serum cholesterol found in the univariate analysis was also found in several preliminary multivariate analyses, but did not reach statistical significance in the final model. However, this relationship should be tested in other therapeutic trials in progress or recently completed.(ABSTRACT TRUNCATED AT 250 WORDS)