Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 Nausea	40		Risk Ratio (IV, Random, 95% CI)	Subtotals only
1.1 All trials	40	4742	Risk Ratio (IV, Random, 95% CI)	0.68 [0.60, 0.77]
1.2 Children	2	258	Risk Ratio (IV, Random, 95% CI)	0.63 [0.51, 0.80]
1.3 Adults	36	4344	Risk Ratio (IV, Random, 95% CI)	0.70 [0.61, 0.79]
1.4 Invasive PC6 stimulation	7	896	Risk Ratio (IV, Random, 95% CI)	0.56 [0.39, 0.80]
1.5 Noninvasive PC6 stimulation	33	3846	Risk Ratio (IV, Random, 95% CI)	0.71 [0.62, 0.81]
1.6 Low risk of bias trials	2	169	Risk Ratio (IV, Random, 95% CI)	0.40 [0.17, 0.93]
1.7 Unclear risk of bias trials	20	2496	Risk Ratio (IV, Random, 95% CI)	0.68 [0.56, 0.82]
1.8 High risk of bias trials	11	1090	Risk Ratio (IV, Random, 95% CI)	0.68 [0.55, 0.85]
1.9 Trials with control event rate less than or equal to 20%	4	454	Risk Ratio (IV, Random, 95% CI)	0.81 [0.49, 1.33]
1.10 Trials with control event rate more than 20%	36	4288	Risk Ratio (IV, Random, 95% CI)	0.68 [0.59, 0.77]
2 Vomiting	45		Risk Ratio (IV, Random, 95% CI)	Subtotals only
2.1 All trials	45	5147	Risk Ratio (IV, Random, 95% CI)	0.60 [0.51, 0.71]
2.2 Children	6	542	Risk Ratio (IV, Random, 95% CI)	0.67 [0.46, 0.97]
2.3 Adults	37	4465	Risk Ratio (IV, Random, 95% CI)	0.61 [0.51, 0.72]
2.4 Invasive PC6 stimulation	7	896	Risk Ratio (IV, Random, 95% CI)	0.51 [0.34, 0.76]
2.5 Noninvasive PC6 stimulation	37	4151	Risk Ratio (IV, Random, 95% CI)	0.60 [0.50, 0.73]
2.6 Low risk of bias trials	2	169	Risk Ratio (IV, Random, 95% CI)	0.52 [0.31, 0.88]
2.7 Unclear risk of bias trials	26	3583	Risk Ratio (IV, Random, 95% CI)	0.59 [0.48, 0.72]
2.8 High risk of bias trials	14	1373	Risk Ratio (IV, Random, 95% CI)	0.62 [0.45, 0.83]
2.9 Trials with control event rate less than or equal to 20%	12	1556	Risk Ratio (IV, Random, 95% CI)	0.75 [0.51, 1.11]
2.10 Trials with control event rate more than 20%	33	3591	Risk Ratio (IV, Random, 95% CI)	0.58 [0.48, 0.69]
3 Rescue antiemetics	39	4622	Risk Ratio (IV, Random, 95% CI)	0.64 [0.55, 0.73]