Comparison 1. Early removal versus late removal of the LMA.

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 Laryngospasm	11	1615	Risk Ratio (M‐H, Random, 95% CI)	1.23 [0.74, 2.03]
1.1 Children	9	1393	Risk Ratio (M‐H, Random, 95% CI)	1.15 [0.69, 1.93]
1.2 Adults	2	222	Risk Ratio (M‐H, Random, 95% CI)	3.93 [0.44, 34.91]
2 Laryngospasm	11	1615	Risk Ratio (M‐H, Random, 95% CI)	1.23 [0.74, 2.03]
2.1 With muscle relaxant	1	156	Risk Ratio (M‐H, Random, 95% CI)	3.0 [0.12, 72.53]
2.2 Without muscle relaxant	10	1459	Risk Ratio (M‐H, Random, 95% CI)	1.20 [0.72, 2.00]
3 Coughing	11	1430	Risk Ratio (M‐H, Random, 95% CI)	0.52 [0.29, 0.94]
3.1 Children	7	835	Risk Ratio (M‐H, Random, 95% CI)	0.50 [0.19, 1.34]
3.2 Adults	5	595	Risk Ratio (M‐H, Random, 95% CI)	0.51 [0.25, 1.03]
4 Coughing	11	1430	Risk Ratio (M‐H, Random, 95% CI)	0.45 [0.23, 0.88]
4.1 With muscle relaxant	2	219	Risk Ratio (M‐H, Random, 95% CI)	0.41 [0.20, 0.83]
4.2 Without muscle relaxant	9	1211	Risk Ratio (M‐H, Random, 95% CI)	0.46 [0.21, 1.04]
5 Desaturation	13	2037	Risk Ratio (M‐H, Random, 95% CI)	0.68 [0.40, 1.16]
5.1 Children	10	1542	Risk Ratio (M‐H, Random, 95% CI)	0.55 [0.26, 1.17]
5.2 Adults	4	495	Risk Ratio (M‐H, Random, 95% CI)	0.91 [0.60, 1.36]
6 Desaturation	13	2037	Risk Ratio (M‐H, Random, 95% CI)	0.65 [0.36, 1.18]
6.1 With muscle relaxant	2	219	Risk Ratio (M‐H, Random, 95% CI)	0.2 [0.01, 4.10]
6.2 Without muscle relaxant	11	1818	Risk Ratio (M‐H, Random, 95% CI)	0.67 [0.37, 1.24]
7 Desaturation	13	2037	Risk Ratio (M‐H, Random, 95% CI)	0.65 [0.36, 1.18]
7.1 < 90%	5	977	Risk Ratio (M‐H, Random, 95% CI)	0.48 [0.21, 1.07]
7.2 > 90% and < 96%	8	1060	Risk Ratio (M‐H, Random, 95% CI)	0.70 [0.31, 1.61]
8 Airway obstruction	8	1313	Risk Ratio (M‐H, Random, 95% CI)	2.69 [1.32, 5.50]
8.1 Children	6	937	Risk Ratio (M‐H, Random, 95% CI)	2.82 [1.28, 6.22]
8.2 Adults	3	376	Risk Ratio (M‐H, Random, 95% CI)	2.46 [0.22, 27.40]
9 Incidence of nausea, vomiting or retching	7	1192	Risk Ratio (M‐H, Random, 95% CI)	0.41 [0.15, 1.13]
9.1 Children	5	936	Risk Ratio (M‐H, Random, 95% CI)	0.45 [0.13, 1.51]
9.2 Adults	2	256	Risk Ratio (M‐H, Random, 95% CI)	0.33 [0.05, 2.08]
10 Incidence of biting on the LMA/LMA damage	2	185	Risk Ratio (M‐H, Random, 95% CI)	0.20 [0.08, 0.51]