Comparison 3. NIV vs UMC ‐ Trial location subgroups.

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 Mortality	10		Risk Ratio (M‐H, Fixed, 95% CI)	Subtotals only
1.1 Intensive care unit	5	251	Risk Ratio (M‐H, Fixed, 95% CI)	0.60 [0.34, 1.07]
1.2 Ward	5	543	Risk Ratio (M‐H, Fixed, 95% CI)	0.48 [0.29, 0.78]
2 Need for endotracheal intubation	16		Risk Ratio (M‐H, Fixed, 95% CI)	Subtotals only
2.1 Intensive care unit	9	401	Risk Ratio (M‐H, Fixed, 95% CI)	0.30 [0.21, 0.43]
2.2 Ward	8	721	Risk Ratio (M‐H, Fixed, 95% CI)	0.43 [0.31, 0.60]