Comparison 1. Leukoreduced PRBC versus non‐leukoreduced PRBC. Main analysis (randomised patients).

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 TRALI. Number of events of the total of randomised patients reported	1	1864	Risk Ratio (M‐H, Random, 95% CI)	0.96 [0.67, 1.36]
2 Death. Number of events of the total of randomised patients reported	9	6485	Risk Ratio (M‐H, Random, 95% CI)	0.81 [0.58, 1.12]
3 Infection. Number of events of the total of randomised patients reported	10	6709	Risk Ratio (M‐H, Random, 95% CI)	0.80 [0.62, 1.03]
4 Adverse events. Number of events of the total of randomised patients reported	2	634	Risk Ratio (M‐H, Fixed, 95% CI)	0.81 [0.64, 1.02]
4.1 Fever	2	634	Risk Ratio (M‐H, Fixed, 95% CI)	0.81 [0.64, 1.02]