Study designs of evaluations included in the review
Randomised, double-blind placebo-controlled trials of AIIAs; randomised controlled trials (RCTs) comparing AIIAs with other established classes of antihypertensive therapy (such as angiotensin-converting enzyme inhibitors, calcium-channel blockers, beta-blockers, and combinations of AIIA with thiazide diuretics, mainly HCTZ); and RCTs in which the antihypertensive efficacy of different AIIAs were compared directly with each other.
Specific interventions included in the review
The inclusion criteria specified that trials have a treatment duration of at least 4 to 6 weeks with starting dose of AIIA before dose titration, then at least another 4 to 6 weeks until final assessment. They were also required to have used one the following dosing regimens: titration as needed (or elective titration), either from starting dose to maximum dose of monotherapy, or from starting dose of monotherapy to a combination of starting dose AIIA with low-dose hydrochlorothiazide (HCTZ); parallel-group comparisons of various doses as monotherapy or AIIA-HCTZ combinations; and forced titration of dose. Trials were excluded if they examined use of AIIA after demonstration of lack of response with a drug from another class, or if they used a dose of AIIA not recommended in the product label.
Specific AIIAs included in the review were: losartan (50 mg, 50 to 100 mg); valsartan (80 mg, 80 to 160 mg); irbesartan (150 mg, 150 to 300 mg); candesartan (8 mg, 8 to 16 mg); losartan (50 mg) plus HCTZ (12.5 mg); valsartan (80 mg) plus HCTZ (12.5 mg); and candesartan (8 mg) plus HCTZ (12.5 mg).
Participants included in the review
Patients with mild-to-moderate hypertension (diastolic blood-pressure 95 to 115 mm Hg) with no concomitant diseases.
Outcomes assessed in the review
Mean blood-pressure reduction (clinical measurement of blood-pressure using sphygmomanometer and cuff). Studies using only ambulatory blood-pressure monitoring were excluded. Final assessment had to take place 4 to 6 weeks after the treatment period had ended.
How were decisions on the relevance of primary studies made?
In order to be included in the meta-analysis, the study had to satisfy the described criteria. The authors do not state how many of the reviewers performed the selection.