Goodwin 1994.

Methods	Multicentre, randomised, placebo‐controlled trial.
Participants	120 women with preterm labour defined as number of contractions: ≥ 6/h (4 centres) and > 4/last 30 min (1 centre), cervical dilatation and effacement: < 2 cm/50% (1 centre), ≤ 3 cm/50% (1 centre), ≤ 3 cm (1 centre), < 2 cm/80% (1 centre), unspecified (1 centre) at gestational age: 20‐35 (1 centre), 20‐34 (1 centre), 25‐35 (1 centre), < 35 (1 centre) and 28‐37 (1 centre) weeks with no change in cervix during ≥ 1 h. Exclusion criteria: prior study participation, ruptured membranes, amnionitis, contraindications to tocolysis, abruptio placenta, fetal distress, lethal fetal anomaly, fetal death.
Interventions	ORA group: atosiban. Infusion rate 300 µg/min for 2 h (i.v.). Control group: placebo. Infusion for 2 h (i.v.).
Outcomes	Percentage change in contractions per h.
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	"A computer‐generated randomisation schedule with a block size of four." The review authors consider this approach low risk.
Allocation concealment (selection bias)	Low risk	"the pharmacist would open the sequentially numbered, opaque, sealed envelope." The review authors consider this approach low risk.
Blinding of participants and personnel (performance bias) All outcomes	Low risk	The personnel preparing the drug was not involved in patient care, and the treatment allocation was not revealed to personnel involved with patient care. The study was placebo‐controlled. The review authors consider this approach low risk.
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Intervention was blinded and risk of outcome assessment bias can be considered low.
Incomplete outcome data (attrition bias) All outcomes	Low risk	4 women in each treatment group were excluded from analyses.
Selective reporting (reporting bias)	Low risk	All outcomes were reported as expected.
Other bias	High risk	The average gestational age in the atosiban group was lower than that of the placebo. The authors consider this to be high risk of introducing bias. Centres had different inclusion criteria which may introduce bias.