Comparison 4. Supplementary analysis: adverse effects.

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 Binary outcomes	1	1066	Risk Ratio (M‐H, Random, 95% CI)	1.36 [0.95, 1.95]
1.1 Vomiting	1	1066	Risk Ratio (M‐H, Random, 95% CI)	1.36 [0.95, 1.95]
2 Continuous outcomes	2	152	Std. Mean Difference (IV, Random, 95% CI)	0.25 [‐0.74, 1.23]
2.1 Cardiorespiratory safety during gastroscopy (heart rate per min)	1	128	Std. Mean Difference (IV, Random, 95% CI)	‐0.19 [‐0.53, 0.16]
2.2 Respiratory depressant response (liter per min)	1	24	Std. Mean Difference (IV, Random, 95% CI)	0.83 [‐0.01, 1.67]