Bollapragada 2006a.

Methods	RCT.
Participants	Setting: large teaching hospital in Glasgow, Scotland, UK. 350 women randomised. Inclusion criteria: primiparous women at term (gestational age > 37 weeks) with singleton pregnancy and Bishop score < 7. Women were scheduled for induction (97% for prolonged pregnancy: 40 weeks + 10 days gestation). Women recruited were willing to self‐administer vaginal tablets. Exclusion criteria: women with ruptured membranes, aged < 16 years age, who needed birth within the next 48 h, or with fetal compromise requiring daily fetal monitoring.
Interventions	Intervention group: self‐administered vaginal IMN 40 mg every 16 h to maximum of 3 doses (48 h, 32 h and 16 h prescheduled admission for induction). Comparison group: self‐administered placebo, same regimen as intervention group.
Outcomes	Time from hospital admission to birth, women's views on induction process, pain, mode of birth, cost to NHS, neonatal outcomes.
Notes	A review author, Jane Norman (JN), was an investigator on this trial. JN was not involved in assessing the eligibility of the study for inclusion, data extraction or assessment of risk of bias. See Eddama 2009 for associated paper on cost outcomes.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Computer generated sequence.
Allocation concealment (selection bias)	Low risk	Central randomisation with automated telephone service. Women were given information and consented after the decision to induce labour had been made. Randomisation in the antenatal clinic up to 9 days before treatment commenced.
Blinding (performance bias and detection bias) Women	Low risk	Treatment packs for intervention and control groups were described as identical, prepared by pharmacy.
Blinding (performance bias and detection bias) Clinical staff	Low risk	Treatment packs for intervention and control groups were described as identical, prepared by pharmacy.
Blinding (performance bias and detection bias) Outcome assessor	Unclear risk	Blinding of outcomes assessors not explicitly stated.
Incomplete outcome data (attrition bias) All outcomes	High risk	350 randomised. 80 women did not initiate treatment as they went in to labour before the scheduled time for taking medication, a further 11 women withdrew (including 2 with breech presentation). All women randomised were included in an ITT analysis for primary outcomes (but not in secondary analysis).
Selective reporting (reporting bias)	Low risk	We examined the protocol for this study and there is no evidence of reporting bias.
Other bias	Low risk	No baseline imbalance apparent.