Liu 2000

Methods	Randomised, double‐blind, multicentre trial. Random number generation done centrally, double‐blinded by use of identical placebos
Participants	100 healthy women recruited in the study from Henan Research Institute for family planning Included women with regular menstrual periods, who had had a single act of unprotected intercourse or had had multi‐intercourse but attended the clinic within 72 h of the first one Excluded women who were breastfeeding, on hormonal contraception in the current cycle and those with uncertain dates of last menstrual period
Interventions	Mife (single dose) 10 mg vs LNG 0.75 mg, 2 doses, 12 h apart, orally
Outcomes	Observed number of pregnancies, side effects and changes in menstrual pattern
Notes	Loss to follow‐up: Mife 2 women; LNG 2 women Observed pregnancy/expected pregnancy/total number of women: Mife 0/4/48; LNG 2/4/48
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)	Low risk	Randomised, double‐blind, multicentre trial. Random number generation done centrally, double‐blinded by use of identical placebos
Blinding (performance bias and detection bias) All outcomes	Low risk	Double‐blind
Incomplete outcome data (attrition bias) All outcomes	Low risk	Loss to follow‐up reported
Selective reporting (reporting bias)	Low risk	Reported planned outcomes
Other bias	Low risk	None detected