He 2002.

Methods	Randomisation by computer. No blinding. No mention of power calculation or intention‐to‐treat analysis.
Participants	China. 60 pregnant women in preterm labour (defined as contracting every 5‐10 minutes lasting 30 seconds with cervix more than 2 cm dilated) between 28 and 37 weeks with intact membranes. No comment on multiple pregnancies. Not blinded. No power calculation mentioned and no intention‐to‐treat analysis mentioned.
Interventions	1. GTN patch 5 mg/24 hrs with another patch added every hr until contractions stopped or 25 mg maximum dose reached. Patches changed every 24 hrs (n = 30). 2. Magnesium sulphate and salbutamol, no doses stated (n = 30).
Outcomes	Percentage of women in whom contractions stopped, days delay of labour, pre and post‐treatment corticotrophin releasing hormone levels.
Notes	No information on whether women got steroids and/or antibiotic therapy. Translated by Cochrane.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Computer‐generated sequence.
Allocation concealment (selection bias)	Unclear risk	Not described.
Blinding of participants and personnel (performance bias) All outcomes	High risk	No blinding.
Blinding of outcome assessment (detection bias) All outcomes	High risk	No blinding.
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Insufficient reporting of attrition and exclusions to permit judgement, e.g. number randomised not stated or no reasons for missing data provided.
Selective reporting (reporting bias)	Unclear risk	Insufficient information to permit a judgement.
Other bias	Unclear risk	Not addressed in translation.