Physicians have come to depend on the results of long-term clinical trials to make treatment decisions. This is true for trials that consider, for example, the management of diabetes, coronary heart disease, hypertension, and malignant diseases.
The recently published Metoprolol Atherosclerosis Prevention in Hypertensives (MAPHY) study,1 which compared the results of a β-blocker, metoprolol, with a diuretic treatment group in moderately severe, middle-aged male hypertensive subjects in 66 centers from 11 countries, presents confusing results with differing interpretations. These should be clarified as quickly as possible before claims resulting from this trial are widely disseminated. This study compared the effects of metoprolol, a selective β-adrenergic inhibiting agent, in 1609 white men (aged 40 to 64 years) with pretreatment diastolic blood pressures between 100 and 130 mm Hg, with those of a thiazide diuretic (hydrochlorothiazide or bendroflumethiazide) in 1625 patients. Mean age was 52 years in each group and serum lipid