a The risk in the intervention group (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI).
CI: confidence interval; RCTs: randomized controlled trials; RR: risk ratio; MD: mean difference; NIHSS = National Institute of Health stroke scale.
High quality: we are very confident that the true effect lies close to that of the estimate of the effect.
Moderate quality: we are moderately confident in the effect estimate: the true effect is likely to be close to the estimate of the effect, but there is a possibility that it is substantially different.
Low quality: our confidence in the effect estimate is limited: the true effect may be substantially different from the estimate of the effect.
Very low quality: we have very little confidence in the effect estimate: the true effect is likely to be substantially different from the estimate of effect.
b A large number of studies were included, a large number of participants participate, and a large confidence interval was calculated (low bias risk).
c Mortality was ’low’ risk of bias.
d We rated down one level: for inconsistency of effect (Heterogeneity was moderate, I2 = 58%).
e We rated down one level: for inconsistency of effect (Heterogeneity was high, I2 = 75%).
f We rated down two levels: one for risk of bias (No random and no allocation concealment), one for imprecision.
g We rated down one levels: for inconsistency of effect (Heterogeneity was high, I2 = 93%).