Comparison 3. Sensitivity analysis by allocation concealment.

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 30‐day mortality	22	10477	Risk Ratio (M‐H, Random, 95% CI)	0.98 [0.82, 1.18]
1.1 Low risk	15	8936	Risk Ratio (M‐H, Random, 95% CI)	1.01 [0.82, 1.24]
1.2 Unclear or high risk	7	1541	Risk Ratio (M‐H, Random, 95% CI)	0.87 [0.56, 1.34]