Kovavisarach 2002.

Methods	Quote: "Random allocation". Method not discussed. Between 1 July 1998 and 31 January 1999 at the gynaecologic clinic at Rajavithi Hospital, Bangkok, Thailand.
Participants	54 women with anembryonic pregnancies < 12 weeks diagnosed by TVS. Single centre study in Bangkok, Thailand.
Interventions	Vaginal misoprostol 400 mcg (n = 27) or placebo (n = 27). Reviewed after 24 hours and curettage offered if no or incomplete miscarriage. Further review after 1 week.
Outcomes	Primary: complete miscarriage within 24 hours of treatment.
Funding	No information on funding.
Declarations of interest	No information on conflicts of interest.
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Quote: "Patients were randomly allocated". Comment: method not discussed.
Allocation concealment (selection bias)	Unclear risk	Comment: no information on allocation concealment.
Incomplete outcome data (attrition bias) All outcomes	Low risk	Comment: 54 women were recruited in the study, for all of them outcomes were reported.
Selective reporting (reporting bias)	Unclear risk	Comment: in the results section several side effects (nausea, pain) are reported that were not mentioned in the methods section; unclear if these were the only side effects that were measured.
Other bias	Low risk	No other source of bias could be detected
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Comment: no information on blinding of patients and personnel. Sinces patients received either misoprostol or placebo it is likely that they were blinded. Blinding of personnel that might recognise misoprostol if the placebo tablets had another shape remains unclear.
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Comment: there is no information on blinding of outcome assessment. Considering that placebo was used as comparison there might have been blinding of the outcome assessor, assuming this was not the person providing the medication (and thus capable of recognising a placebo if it had another shape than the misoprostol).