Comparison 1. Mortality: INO versus control group.

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 Overall mortality: INO vs control	13	1243	Risk Ratio (M‐H, Fixed, 95% CI)	1.04 [0.90, 1.19]
2 28‐ to 30‐day mortality: INO vs control	9	1105	Risk Ratio (M‐H, Fixed, 95% CI)	1.08 [0.92, 1.27]
3 Mortality: subgroup analysis, paediatric vs adult population	13	1243	Risk Ratio (M‐H, Fixed, 95% CI)	1.04 [0.90, 1.19]
3.1 Paediatric	3	185	Risk Ratio (M‐H, Fixed, 95% CI)	0.78 [0.51, 1.18]
3.2 Adult	10	1058	Risk Ratio (M‐H, Fixed, 95% CI)	1.08 [0.93, 1.25]
4 Mortality: subgroup analysis based on duration of drug administration	12	1190	Risk Ratio (M‐H, Fixed, 95% CI)	1.06 [0.92, 1.22]
4.1 Shorter than median duration of INO	5	394	Risk Ratio (M‐H, Fixed, 95% CI)	1.04 [0.84, 1.29]
4.2 Longer than median duration of INO	7	796	Risk Ratio (M‐H, Fixed, 95% CI)	1.07 [0.89, 1.29]
5 Sensitivity analysis: excluding abstracts, INO vs control	11	1021	Risk Ratio (M‐H, Fixed, 95% CI)	1.02 [0.87, 1.21]
6 Sensitivity analysis: excluding trials not fulfilling AECC criteria, INO vs control	10	834	Risk Ratio (M‐H, Fixed, 95% CI)	1.08 [0.92, 1.26]