| Study | Reason for exclusion |
|---|---|
| Agarwal 2005 | PC6 acupoint stimulation not used. Authors used Korean hand acupressure point K‐D2 in the study. |
| Al‐Sadi 1997 | No sham treatment group used. Control was defined as no intraoperative acupuncture needle at PC6 acupoint. |
| Alkaissi 2005 | Participants did not undergo surgery. |
| Cekmen 2007 | PC6 acupoint stimulation not used. Authors used transcutaneous electrical nerve stimulation on neck and mastoid area. |
| Chen 2005 | No sham treatment group used. |
| Coloma 2002 | Treatment of established postoperative nausea and vomiting. |
| Dundee 1988 | Incidences of nausea and vomiting were not reported separately. |
| Dundee 1991 | 2 different forms of PC6 stimulation (acupuncture + saline, acupuncture + 1% lidocaine). No sham treatment group used. |
| El‐Bandrawy 2013 | Severity of nausea and vomiting symptoms assessed, not incidence. |
| El‐Rakshy 2009 | Multiple acupoints used. |
| Fan 1997 | Incidences of nausea and vomiting were not reported separately. |
| Fry 1986 | No sham treatment group used. Control was defined as no acupressure treatment. Participants did not know that they were in the trial. |
| Grube 2009 | Multiple acupoints used (Hegu, Quchi, Neiguan, Zusanli, Neiting, Sanyinjiao, Daichong). |
| Hirs 2013 | Ambiguous details about group allocation following results of unpublished pilot study. |
| Ho 2006 | Prevention of intraoperative nausea and vomiting, not postoperative outcomes. |
| Jin 2013 | No sham PC6 acupoint stimulation group. |
| Kabalak 2005 | Both Pericardium and Shangwan acupoints used. No treatment was given to the control group. |
| Khan 2004 | Incidences of nausea and vomiting were not reported separately. |
| Kim 2002 | Control was defined as an inactive capsicum plaster tape fixed at the Korean hand acupuncture point K‐D2 point of both hands. |
| Kim 2010 | Control group appears to be no‐treatment. Unable to get full text. |
| Klaiman 2008 | Incidences of nausea and vomiting were not reported separately. |
| Korinenko 2009 | Multiple acupoints used. |
| Larson 2010 | Severity of nausea and vomiting symptoms assessed, not incidence. |
| Lee 2008 | No sham treatment group used. |
| Lee 2013 | No sham treatment group used. |
| Liodden 2011 | Control group was standard care without acupuncture/acupressure. |
| Lu 2013 | No sham treatment group used. |
| McConaghy 1996 | Treatment of established postoperative nausea and vomiting. |
| McMillan 1994 | All transcutaneous electrical stimulation at PC6 acupoint groups received antiemetics. Incidences of nausea and vomiting were not reported separately for placebo transcutaneous electrical stimulation and transcutaneous electrical stimulation groups. |
| Ming 2002 | Multiple acupoints used. |
| Ng 2011 | Incidences of nausea and vomiting were not reported separately. |
| Norheim 2010 | Control group was standard care without acupuncture/acupressure. |
| Noroozinia 2013 | Prevention of intraoperative nausea and vomiting, as well as postoperative nausea and vomiting. Unclear how long acupressure wristband was applied on for. Metoclopramide given for intraoperative nausea and vomiting will affect subsequent PONV incidence comparisons. |
| Ouyang 2009 | No sham treatment group used. Control was defined as no acupuncture at PC6 acupoint before and during anaesthesia. |
| Phillips 1994 | No sham treatment group used. No specific details of the type of antiemetic drug used as control. |
| Schwager 1996 | Both PC6 and Li4 acupoints stimulated. |
| Shyr 1990 | Control was defined as no acupuncture at PC6 acupoint. |
| Sinha 2011 | Nausea and vomiting during labour and delivery, not postoperative outcomes. |
| Somri 2001 | Multiple acupoints used. |
| Stein 1997 | Prevention of intraoperative nausea and vomiting. |
| Tang 2013 | No sham treatment group used. |
| Wang 2014 | Multiple acupoints used. |
| Weightman 1987 | No sham treatment group used. Control was defined as no acupuncture at PC6 acupoint after induction of anaesthesia. |
| White 2005 | This study compared 3 prophylactic acu‐stimulation treatments: preoperative, postoperative, and both preoperative and postoperative. No sham treatment group used for both preoperative and postoperative acu‐stimulation. |
| Windle 2001 | Retrospective chart review was used to estimate the incidence of vomiting. Incidences of nausea and vomiting were not considered separately, and results were not presented in the paper. |
| Yeh 2010 | Multiple acupoints used for pain and PONV. |
| Yentis 1991 | No sham treatment group used. Control was no acupuncture treatment at PC6 acupoint. |
| Yentis 1998 | This study compared acupuncture given before induction, after induction and in the recovery room. No sham treatment or antiemetic drug group for comparison. |
| Zheng 2008 | Multiple acupoints used. |
IV ‐ intravenous K‐D2 = Korean hand acupuncture K‐D2 point PC = pericardium acupoint PONV = postoperative nausea and vomiting