Methods	A randomised blinded study.
Participants	90 pregnant women, with gestation of 12 weeks or less by the completion of the study. Exclusion criteria were diagnosed hyperemesis gravidarum, diseases that cause nausea and emesis, and current use of anti-emetic medication
Interventions	Treatment group received acupressure using an acupressure point (Nei Guan PC-6); placebo point (on palmar surface of the hand, proximal to the head of the fifth metacarpal joint) used for the sham control group. Applied for 10 minutes 4 times per day
Outcomes	Nausea and vomiting were measured using the Rhodes Index of Nausea and Vomiting Form-2 (scale range of 0-32, 3 subscales: nausea (duration, frequency and distress), vomiting (amount, frequency and distress) and retching (frequency and distress) Outcomes were measured each evening for 10 consecutive days; data from the first 3 days were used as pre-treatment data; data from days 5-7 were used to measure treatment effect
Notes
Risk of bias
Item	Authors’ judgement	Description
Adequate sequence generation?	Yes	Women were assigned by a randomised block design to P6 acupressure or sham acupressure group. How this was done is not described. Probably adequate, though size of blocks not stated
Allocation concealment?	Unclear	Not described.
Blinding? Change in grade of nausea or vomiting at second visit compared to first	Yes	Subjects and their referring practitioners were blind to the group assignment (though this presupposes a lack of knowledge of acupressure). Subjects self-reported outcomes
Incomplete outcome data addressed? Change in grade of nausea or vomiting at second visit compared to first	Yes	30 of 90 participants did not complete the study (16 treatment and 14 control). Failure to return forms, very incomplete forms or loss to follow up explained attrition of 13 treatment and 12 control participants. The remaining attrition (3 treatment and 2 control) was explained as prescribing anti-emetics, abdominal surgery and voluntary dropout Though this high attrition rate might introduce bias, it is similar between groups
Free of selective reporting?	No	Retching subscale results not reported. Subscale results for nausea and vomiting presented averaged for days 1-3 and 5-7; data from days 8, 9, 10 were not presented; it was reported in text that data from these days “demonstrated no significant differences between the treatment and placebo groups because nausea and vomiting had improved over time” (average gestation 8.5 weeks +/− 1. 4 weeks)
Free of other bias?	Yes	Internal reliability of Rhodes Index reported for day 2 of pre-treatment (r = 0.88); not explained why this day was chosen. Unlikely to introduce bias