French/Australian 2001.

Methods	Multicentre, randomised, placebo‐controlled trial.
Participants	241 women with preterm labour, defined as duration of contractions ≥ 30 sec at a rate of ≥ 4/30 min, cervical dilation 0‐3 cm (nullipara) or 1‐3 cm (primi‐ or multipara) and effacement ≥ 50%, at 23‐33 completed weeks' gestation and ≥ 18 years of age. Exclusion criteria: multiple pregnancy (> twins), ruptured membranes, major vaginal bleeding, use of NSAID's within 12 h (Australia), ß‐agonists within 30 min and NSAID's or calcium channel blockers within 24 h (France), severe pre‐eclampsia or hypertension, temperature > 37.5ºC, urinary tract infection, fetal/placental abnormalities (e.g. chorioamnionitis, abruptio placenta, placenta praevia, intrauterine growth retardation, fetal distress/death, major congenital anomaly, hydramnios, retained intrauterine device), serious maternal disease (e.g. cardiovascular disease, hyperthyroidism, uncontrolled diabetes mellitus, pheochromocytoma, asthma), contraindication to salbutamol, alcohol or drug abuse, hypersensitivity to any components of the study drugs, participation in a clinical trial < 1 month, significant renal impairment (Australia).
Interventions	ORA group: atosiban. Bolus dose 6.75 mg (i.v.) followed by infusion at 300 µg/min for 3 h then 100 µg/min up to 48 h. A placebo i.v. infusion of 5% dextrose was given separately but simultaneously. Control group: salbutamol. Bolus injection of 0.9 mL NaCl followed by i.v. infusion of 5% dextrose. Separately but simultaneously salbutamol was given as an i.v. infusion in 5% dextrose at 5‐25 µg/min (France) or 2.5‐45 µg/min (Australia). Both infusions were continued for 48 h.
Outcomes	Primary goals were the safety and effectiveness of atosiban versus terbutaline as tocolytic agents, assessed as women undelivered after 48 h and 7 days and maternal side effects. Secondary outcomes: contraction rate with time, gestational age at delivery, proportion of women re‐treated with study medication, proportion of infants born at differing gestational age and number of infants requiring neonatal intensive care.
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	"Computer‐generated randomisation lists for each center was used to allocate women to study treatment and women were stratified by gestational age at enrolment." The review authors consider this approach low risk.
Allocation concealment (selection bias)	Low risk	Prepared by Ferring Pharmaceuticals: computer‐generated randomisation stratified by GA and centre, supplied to pharmacists at each centre in pre‐randomised boxes labelled with country code and case number.
Blinding of participants and personnel (performance bias) All outcomes	Low risk	"Through the use of a double‐blind, double‐dummy technique, the utmost effort was made to keep the study blinded. […] the somewhat obvious side effects profile of terbutaline may have compromised the blinding." The review authors consider this approach low risk.
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Probably low risk as double‐placebo technique was used.
Incomplete outcome data (attrition bias) All outcomes	Low risk	1 woman in the salbutamol group was lost to follow‐up.
Selective reporting (reporting bias)	Low risk	All outcomes were reported as expected.
Other bias	Low risk	None apparent.