Wang 2001

Methods	Randomised, double‐blind, multicentre trial. Random number generation done centrally, double‐blinded by use of identical placebos
Participants	200 healthy women recruited in the study from an obs/gyn clinic in Wuhan, China Included women with regular menstrual periods, aged 22‐42 years, who had attended the clinic within 72 h of a single act of unprotected intercourse Excluded women who were on hormonal contraception in the current cycle and those with uncertain dates of last menstrual period
Interventions	Mife 10 mg, single dose vs Mife 25 mg, orally
Outcomes	Observed number of pregnancies, side effects and changes in menstrual pattern
Notes	Post‐randomisation exclusion and loss to follow‐up not reported Observed pregnancy/expected pregnancy/total number of women: Mife 10 mg 1/10/100; Mife 25 mg 1/10/100
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Random number generation done centrally
Allocation concealment (selection bias)	Unclear risk	Method of allocation concealment not mentioned
Blinding (performance bias and detection bias) All outcomes	Low risk	Double‐blind
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Post‐randomisation exclusion and loss to follow‐up not reported
Selective reporting (reporting bias)	Low risk	Reported planned outcomes
Other bias	Low risk	None detected