Tang 2006.

Methods	Open parallel RCT. Eligible women were randomised according to computer‐generated random numbers into 2 groups. The study was carried out from July, 2002 to January, 2004; Queen Mary Hospital, Hong Kong SAR, China.
Participants	Women with (i) intrauterine gestational sac with a mean sac diameter of ≥ 2 cm without a fetal pole; (ii) presence of a fetal pole with no cardiac pulsation; (iii) the gestational sac was < 2 cm with no interval growth or persistent absence of fetal cardiac pulsation on rescanning 7–10 days later.
Interventions	Women in both groups (total n = 180) received 600 mcg misoprostol sublingually every 3 hours for a maximum of 3 doses (day 1). Additionally, women in group 2 (n = 90) also received 400 mcg misoprostol sublingually daily for a further week (day 2–8).
Outcomes	The outcome of the study was assessed on day 9. A transvaginal ultrasound examination of the pelvis was performed The primary outcome measure was the complete miscarriage rate. The incidence of side effects, duration of vaginal bleeding and the change in haemoglobin level were also studied.
Funding	The work described in this paper was supported by a grant from the Committee on Research and Conference Grants of The University of Hong Kong of the Hong Kong Special Administrative Region, China.
Declarations of interest	No information on conflicts of interest.
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: "Eligible women were randomized according to computer‐generated random numbers into two groups".
Allocation concealment (selection bias)	Unclear risk	Comment: no information on allocation concealment.
Incomplete outcome data (attrition bias) All outcomes	Low risk	Comment: according to the flowchart, there was no loss to follow up and no missing data.
Selective reporting (reporting bias)	Unclear risk	Comment: table 3 shows several side effects. The methods section only states that 'side effects' were measured without further specification. It is unclear if the effects mentioned in table 3 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	High risk	Quote: "This was an open randomized study and both the subjects and the investigators knew the treatment that the women had received". Comment: due to the nature of the interventions blinding was practically impossible.
Blinding of outcome assessment (detection bias) All outcomes	High risk	Comment: there is no information on blinding of outcome assessment available; it seems that outcome was not assessed by an independent doctor.