Comparison 4. Subgroup analysis ‐ length of ventilation.

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 Artificial airway occlusion	15		Risk Ratio (M‐H, Random, 95% CI)	Subtotals only
1.1 Medium‐term	8	1031	Risk Ratio (M‐H, Random, 95% CI)	1.74 [0.41, 7.30]
1.2 Long‐term	7	1140	Risk Ratio (M‐H, Random, 95% CI)	1.47 [0.34, 6.36]
2 All‐cause mortality	11		Risk Ratio (M‐H, Random, 95% CI)	Subtotals only
2.1 Medium‐term	5	860	Risk Ratio (M‐H, Random, 95% CI)	1.01 [0.78, 1.31]
2.2 Long‐term	6	1048	Risk Ratio (M‐H, Random, 95% CI)	1.03 [0.85, 1.25]
3 Pneumonia	11		Risk Ratio (M‐H, Random, 95% CI)	Subtotals only
3.1 Medium‐term	5	892	Risk Ratio (M‐H, Random, 95% CI)	1.06 [0.77, 1.47]
3.2 Long‐term	6	1036	Risk Ratio (M‐H, Random, 95% CI)	0.91 [0.59, 1.43]