Comparison 1. NIPPV versus no NIPPV.

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 Pulmonary complications	5	346	Risk Ratio (M‐H, Fixed, 95% CI)	1.03 [0.72, 1.47]
1.1 Bi‐level	2	53	Risk Ratio (M‐H, Fixed, 95% CI)	0.76 [0.27, 2.13]
1.2 CPAP	3	293	Risk Ratio (M‐H, Fixed, 95% CI)	1.08 [0.74, 1.59]
2 Rate of intubation	2	69	Risk Ratio (M‐H, Fixed, 95% CI)	0.55 [0.25, 1.20]
2.1 Bi‐level	2	69	Risk Ratio (M‐H, Fixed, 95% CI)	0.55 [0.25, 1.20]
3 Mortality	5	259	Risk Ratio (M‐H, Fixed, 95% CI)	0.60 [0.24, 1.53]
3.1 Bi‐level	3	101	Risk Ratio (M‐H, Fixed, 95% CI)	0.33 [0.10, 1.08]
3.2 CPAP	2	158	Risk Ratio (M‐H, Fixed, 95% CI)	3.06 [0.33, 28.67]
4 Length of intensive care unit stay	2	69	Mean Difference (IV, Fixed, 95% CI)	‐0.75 [‐3.93, 2.43]
4.1 Bi‐level	2	69	Mean Difference (IV, Fixed, 95% CI)	‐0.75 [‐3.93, 2.43]
5 Length of hospital stay	4	209	Mean Difference (IV, Random, 95% CI)	‐0.12 [‐6.15, 5.90]
5.1 Bi‐level	3	101	Mean Difference (IV, Random, 95% CI)	1.01 [‐9.81, 11.84]
5.2 CPAP	1	108	Mean Difference (IV, Random, 95% CI)	0.40 [‐0.94, 1.74]