Creinin 2006

Methods	Randomised, double‐blinded, non‐inferiority trial Study drug was supplied in sequentially‐numbered, sealed packages containing 2 opaque capsules. The packages either contained a single opaque capsule with UPA (CDB‐2914) 50 mg plus an identical placebo capsule or 2 opaque capsules, each with a tablet of LNG 0.75 mg The identification of the contents of the capsules was unknown to the investigators and the subjects
Participants	1672 healthy women aged at least 18 years of age not using any hormonal contraception who requested EC within 72 h after unprotected intercourse as a result of using no contraception, condom breakage or slippage, or failure of another barrier method To be eligible for enrolment, they were required to have had a recent history of regular menstrual cycles (24‐42 days). At least 1 normal menstrual cycle (2 menses) was required after delivery, abortion or discontinuation of hormonal contraceptive
Interventions	Women randomly assigned to receive a single dose of UPA (CDB‐2914) 50 mg plus a placebo 12 h later or 2 doses of LNG 0.75 mg taken 12 h apart
Outcomes	Observed number of pregnancies, side effects and changes in menstrual pattern
Notes	Loss of follow‐up: UPA 40/832; LNG 54/840 Post‐randomisation exclusions: UPA 17/832; LNG 12/840 Observed pregnancy/expected pregnancy/total number of women: UPA 7/47/775; LNG 13/42/774
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	"Randomization was performed in blocks of eight such that, within each block of study drug, the chance of getting each treatment was equal."
Allocation concealment (selection bias)	Low risk	"The study drug was supplied in sequentially numbered sealed packages containing two opaque capsules. The packages either contained a single opaque capsule with 50 mg of CDB‐2914 plus an identical placebo capsule, or two opaque capsules, each with a tablet of 0.75 mg of levonorgestrel. The identification of the contents of the capsules was unknown to the investigators and the subjects. A portion of the label on each package of study drug was affixed to the case report form. This portion of the label had a removable opaque panel to allow for emergency unblinding. Once removed, these labels could not be replaced." "If the woman’s urine pregnancy test was negative, the next sequentially numbered envelope was then opened and the first dose of study drug taken in the office."
Blinding (performance bias and detection bias) All outcomes	Low risk	"The study drug was supplied in sequentially numbered sealed packages containing two opaque capsules. The packages either contained a single opaque capsule with 50 mg of CDB‐2914 plus an identical placebo capsule, or two opaque capsules, each with a tablet of 0.75 mg of levonorgestrel. The identification of the contents of the capsules was unknown to the investigators and the subjects. A portion of the label on each package of study drug was affixed to the case report form. This portion of the label had a removable opaque panel to allow for emergency unblinding. Once removed, these labels could not be replaced."
Incomplete outcome data (attrition bias) All outcomes	Low risk	Explains loss to follow‐up. Used ITT analysis
Selective reporting (reporting bias)	Low risk	Planned outcomes in the protocol were reported in paper
Other bias	Low risk	None detected