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 .
Beta-blockers versus diuretics in hypertensive men: main results from the HAPPHY trial.
Men aged 40 - 64 years with mild to moderate hypertension [ diastolic blood pressure ( DBP ) 100 - 130 mmHg ] were r and omized to treatment with a  diuretic ( n = 3272 ) or a  beta-blocker ( n = 3297 ) , with additional drugs if necessary , to determine whether a beta-blocker based treatment differs from thiazide diuretic based treatment with regard to the prevention of coronary heart disease ( CHD ) events and death .  Patients with previous CHD , stroke or other serious diseases , or with contraindications to diuretics or beta-blockers were excluded . If normotension ( DBP less than 95 mmHg ) was not achieved by monotherapy , other antihypertensive drugs were added , but the two basic drugs were not crossed over . Patients were assessed at 6-monthly intervals . The mean follow-up for end-points was 45.1 months . Blood pressure ( BP ) side effects and end-points were recorded in a st and ardized manner . Entry characteristics and the BP reduction achieved were very similar in both treatment groups . All analyses were made on an intention-to-treat basis . The incidence of CHD did not differ between the two treatment groups . The incidence of fatal stroke tended to be lower in the beta-blocker treated group than in the diuretic treated group . Total mortality and the total number of end-points were similar in both groups . The percentage of patients withdrawn due to side effects was similar , whereas the number of reported symptoms , according to a question naire , was higher for patients on beta-blockers . The incidence of diabetes did not differ between the two groups . Subgroup analyses did not detect a difference in the effect of beta-blockers compared with diuretics in smokers as opposed to non-smokers , and beta-blockers also had the same effects as diuretics in the quartile with the highest predicted risk for CHD . Beta-blockers and thiazide diuretics were approximately equally well tolerated . The two drugs had a similar BP reducing effect although additional drugs had to be given more often in the diuretic group . Antihypertensive treatment based on a beta-blocker or on a thiazide diuretic could not be shown to affect the prevention of hypertensive complications , including CHD , to a different extent
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 .