Nicoll 2001.

Methods	Randomly allocated using random number tables in permuted blocks of 12. Concealment sealed, opaque sequentially numbered envelopes. Inpatient setting. Recruitment between August 1998 and July 1999 Dept of Obstetrics and Gynecology, University of Glasgow and Glasgow Royal Maternity Hospital.
Participants	Inclusion criteria: not stated. Exclusion criteria: Bishop score > 7, multiple pregnancy, history of antepartum haemorrhage, pregnancy‐induced hypertension or pre‐eclampsia, breech presentation, fetal abdominal circumference < 5th percentile, AFI < 5th percentile, history of cardiorespiratory disease, history of headache.
Interventions	38 recruited, 36 women randomised into 3 groups 13 women received vaginally‐administered ISMN (20 mg), 11 women received vaginally‐administered ISMN (40 mg), 12 women received a vaginal examination only. Women who failed to achieve a Bishop score of > 7, 360 minutes after treatment allocation underwent an amniotomy.   The women filled out a symptom questionnaire and had their cervical score assessed pretreatment administration and 360 minutes after administration.
Outcomes	Maternal: caesarean section, instrumental vaginal delivery and maternal side effects (headache). Neonatal: NICU admission.
Notes	Only data comparing the 40 mg ISMN group to placebo were analysed.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Randomly allocated using random number tables in permuted blocks of 12.
Allocation concealment (selection bias)	Low risk	Sealed, opaque sequentially numbered envelopes.
Incomplete outcome data (attrition bias) All outcomes	Low risk	No evidence to the contrary.
Selective reporting (reporting bias)	Low risk	No evidence to the contrary.
Other bias	Low risk	No evidence to the contrary.
Blinding of participants and personnel (performance bias) All outcomes	Low risk	This was a double‐blinded study and independent observer administrated the treatment. The assessment of the cervix was carried out by the same assessor to reduce individual variation. The patient was not aware of the treatment given.
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	The assessment of the cervix was carried out by the same assessor to reduce individual variation.