Zhao 2011.

Methods	Single centre randomised controlled trial in which 35 participants received loop ligation combined with vasopressin, 35 participants received vasopressin alone and 35 participants received neither loop ligation nor vasopressin From January 2006 to January 2008 No power calculation performed
Participants	Setting: Sheng Jing Hospital, China Medical University Women with symptomatic myomas (diameter ≥ 6cm) needing surgical treatment Ethnicity not reported Age ranges from 22 to 49 years
Interventions	Group A: loop ligation of larger myoma pseudocapsules combined with vasopressin; group B: vasopressin injection; and group C: neither loop ligation nor vasopressin injection. Vasopressin injection consisted of 6U diluted with 20ml of normal saline and injected into the myometrium and myoma. All patients had laparoscopic myomectomy. Blood loss was measured by suction irrigator through subtracting the fluid used from the total measured loss
Outcomes	The outcomes measured were blood loss, operating time, postoperative stay, blood transfusions, conversion to laparotomy
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	It is stated that patients were randomly divided into three groups by ‘simple random method’. No details are given to explain the simple random method
Allocation concealment (selection bias)	Unclear risk	The randomisation was concealed from the surgeon until before the start of the operation. No further details are given
Incomplete outcome data (attrition bias) All outcomes	Low risk	No incomplete outcome data
Selective reporting (reporting bias)	Unclear risk	We do not have access to the study protocol
Other bias	Low risk	No other sources of bias identified
Blinding of participants and personnel (performance bias) All outcomes	High risk	The control group receive no treatment rather than an identical placebo
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	No information