Comparison 3. Sensitivity analysis by allocation concealment.

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
3.1 30‐Day mortality	31	16729	Risk Ratio (M‐H, Random, 95% CI)	0.99 [0.86, 1.15]
3.1.1 Low risk of bias	26	15764	Risk Ratio (M‐H, Random, 95% CI)	1.01 [0.87, 1.18]
3.1.2 Unclear or high risk of bias	5	965	Risk Ratio (M‐H, Random, 95% CI)	0.84 [0.51, 1.39]