INTERPRETATION Drug-class effects on interindividual variation in blood pressure can account for differences in effects of antihypertensive drugs on risk of stroke independently of effects on mean SBP .
INTRODUCTION Unexplained differences between classes of antihypertensive drugs in their effectiveness in preventing stroke might be due to class effects on intraindividual variability in blood pressure .
We did a systematic review to assess any such effects in r and omised controlled trials .
Randomized double-blind comparison of a calcium antagonist and a diuretic in elderly hypertensives. National Intervention Cooperative Study in Elderly Hypertensives Study Group.
Although diuretics are recommended for the treatment of hypertension , decreased diuretic use and increased calcium antagonist use necessitate a comparison of the efficacy of these drugs in preventing cardiovascular events .  Patients > /=60 years of age with systolic blood pressure of 160 to 220 mm Hg and diastolic blood pressure < 115 mm Hg were enrolled . Patients were r and omly assigned to 20 mg of sustained-release nicardipine hydrochloride twice daily or 2 mg of trichlormethiazide once daily by the double-dummy method and followed up for 5 years . A total of 414 patients were analyzed : 204 in the nicardipine group and 210 in the diuretic group .  Blood pressure  at entry was 172/94 mm Hg and 173/93 mm Hg , respectively , and decreased to 147/81 mm Hg and 147/79 mm Hg , respectively . Cardiovascular morbidity rates per 1000 persons per year were similar in the nicardipine and diuretic groups ( 27.8 and 26.8 , respectively ; P=0.923 ) . The sex- and age-adjusted risk ratio for the nicardipine group was 0.973 ( 95 % confidence interval , 0.514 to 1.839 , P=0.932 ) . The calcium antagonist and diuretic groups had a similarly decreased rate of cardiovascular events
INTERPRETATION Drug-class effects on interindividual variation in blood pressure can account for differences in effects of antihypertensive drugs on risk of stroke independently of effects on mean SBP .
INTRODUCTION Unexplained differences between classes of antihypertensive drugs in their effectiveness in preventing stroke might be due to class effects on intraindividual variability in blood pressure .
We did a systematic review to assess any such effects in r and omised controlled trials .