RESUMEN
OBJECTIVE: To assess the equivalence of four antihypertensive treatments in patients with mild-to- moderate hypertension, and to compare the effects of those drugs on the subjective quality of life and clinical safety. DESIGN, SETTING AND PATIENTS: 653 patients aged > or = 18 years with untreated hypertension were randomly allocated to receive a combination of two diuretics (altizide and spironolactone), a beta-blocker (bisoprolol), a calcium antagonist (verapamil), or an angiotensin converting enzyme (ACE) inhibitor (enalapril). Follow-up lasted for 1 year. MAIN OUTCOME MEASURES: A composite outcome of the following measures was used to define success: attendance at the 12-month visit; at least nine supine DBP measurements during the study; and median supine DBP < 90 mmHg and a reduction of at least 10 mmHg compared with the baseline value. Failure was defined as one or more of those criteria not being fulfilled. Equivalence was concluded if the 95% confidence interval for the success rates differed between two groups by less than +/- 10%. Clinical safety and subjective quality of life were also assessed. RESULTS: No statistically significant differences in the change in DBP or systolic blood pressure were observed between the groups. The success rates were 43.9, 42.0, 32.5 and 43.9% in diuretic, beta-blocker, calcium antagonist and ACE inhibitor groups, respectively. Equivalence between the treatments could not be concluded, although analysis with a larger equivalence interval showed that some comparisons indicated equivalence. Significant improvement in satisfaction was observed for certain items for subjective quality of life at 1 month in the calcium antagonist treatment group, and significant differences in the responses to the clinical safety questionnaire were observed after 1-month follow-up in calcium antagonist and beta-blocker groups. Differences were no longer significant after 9 months. CONCLUSIONS: These results do not provide evidence on the basis of efficacy of blood pressure lowering or ability to increase short-term (1-year) safety and quality of life favouring any particular treatment among the studied drugs for newly diagnosed patients with mild-to-moderate hypertension.