Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 Nausea	8		Risk Ratio (IV, Random, 95% CI)	Subtotals only
1.1 PC6 acupoint stimulation and droperidol	2	128	Risk Ratio (IV, Random, 95% CI)	0.77 [0.15, 4.10]
1.2 PC6 acupoint stimulation and ondansetron	4	295	Risk Ratio (IV, Random, 95% CI)	0.79 [0.47, 1.33]
1.3 PC6 acupoint stimulation, dexamethasone and ondansetron	2	219	Risk Ratio (IV, Random, 95% CI)	0.69 [0.50, 0.93]
1.4 All PC6 acupoint stimulation and antiemetic combinations	8	642	Risk Ratio (IV, Random, 95% CI)	0.79 [0.55, 1.13]
1.5 Invasive PC6 stimulation	2	120	Risk Ratio (IV, Random, 95% CI)	0.28 [0.11, 0.75]
1.6 Noninvasive PC6 stimulation	6	522	Risk Ratio (IV, Random, 95% CI)	0.88 [0.62, 1.25]
1.7 Low risk of bias trials	1	119	Risk Ratio (IV, Random, 95% CI)	0.58 [0.38, 0.88]
1.8 Unclear risk of bias trials	4	355	Risk Ratio (IV, Random, 95% CI)	0.86 [0.61, 1.20]
1.9 High risk of bias trials	3	168	Risk Ratio (IV, Random, 95% CI)	0.58 [0.12, 2.66]
1.10 Trials with control event rate less than or equal to 20%	1	40	Risk Ratio (IV, Random, 95% CI)	0.14 [0.01, 2.60]
1.11 Trials with control event rate more than 20%	7	602	Risk Ratio (IV, Random, 95% CI)	0.81 [0.56, 1.16]
2 Vomiting	9		Risk Ratio (IV, Random, 95% CI)	Subtotals only
2.1 PC6 acupoint stimulation and droperidol	3	173	Risk Ratio (IV, Random, 95% CI)	0.62 [0.19, 1.99]
2.2 PC6 acupoint stimulation and ondansetron	4	295	Risk Ratio (IV, Random, 95% CI)	0.51 [0.20, 1.30]
2.3 PC6 acupoint stimulation and dexamethasone and ondansetron	2	219	Risk Ratio (IV, Random, 95% CI)	0.49 [0.30, 0.79]
2.4 All PC6 acupoint stimulation and antiemetic combinations	9	687	Risk Ratio (IV, Random, 95% CI)	0.56 [0.35, 0.91]
2.5 Children	1	60	Risk Ratio (IV, Random, 95% CI)	0.83 [0.43, 1.63]
2.6 Adult	8	627	Risk Ratio (IV, Random, 95% CI)	0.51 [0.29, 0.91]
2.7 Invasive PC6 stimulation	3	180	Risk Ratio (IV, Random, 95% CI)	0.34 [0.08, 1.40]
2.8 Noninvasive PC6 stimulation	6	507	Risk Ratio (IV, Random, 95% CI)	0.65 [0.38, 1.11]
2.9 Low risk of bias trials	1	119	Risk Ratio (IV, Random, 95% CI)	0.53 [0.30, 0.94]
2.10 Unclear risk of bias trials	4	355	Risk Ratio (IV, Random, 95% CI)	0.52 [0.25, 1.09]
2.11 High risk of bias trials	4	213	Risk Ratio (IV, Random, 95% CI)	0.56 [0.19, 1.64]
2.12 Trials with control event rate less than or equal to 20%	2	120	Risk Ratio (IV, Random, 95% CI)	0.13 [0.02, 1.04]
2.13 Trials with control event rate more than 20%	7	567	Risk Ratio (IV, Random, 95% CI)	0.61 [0.37, 1.00]
3 Rescue antiemetic	5	419	Risk Ratio (IV, Random, 95% CI)	0.61 [0.44, 0.86]