CI: Confidence interval; DBP: diastolic blood pressure; RR: risk ratio; SBP: systolic blood pressure; ROB: risk of bias.
GRADE Working Group grades of evidence: High quality: further research is very unlikely to change our confidence in the estimate of effect; Moderate quality: further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate; Low quality: further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate; Very low quality: we are very uncertain about the estimate.
a  The basis for the assumed risk (e.g. the median control group risk across studies) is provided in these footnotes. The corresponding risk (and its 95% CI) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI).
b  According to the ROB graph (Supplementary Material Figure 1).
c  Funnel plot was asymmetrical.