Methods	Cluster-randomised trial in Newcastle, New South Wales, Australia
Participants	Women attending 22 public antenatal clinics (unit of randomisation). Exclusion criteria: under 16 years of age, too sick, non-English speaking, illiterate, attendance was first visit. 194 women included in the analysis
Interventions	Intensive dissemination of programme (Intervention group) included written information and feedback about programme benefits to managers, provision of programme resources, offers of visits to explain programme and provide training, sample smoking cessation policy, regular contacts to offer support, and computerised feedback on activities. Simple dissemination of programme to clinics (control group) included mail out of written information on programme benefit and resources. The cessation programme “Fresh Start for you and your baby”, developed by Windsor, based on CBT, was used Intervention intensity: I = 4, C = 4 (same intervention in both groups, only dissemination method differed)
Outcomes	Biochemically validated smoking cessation at end of pregnancy, recall of smoking advice received Participants and provider views of interventions discussed.
Notes	Process evaluation showed good implementation in intervention group. No intracluster correlation or impact factor reported, so sensitivity analysis conducted using four ICCs and figures adjusting using ICC of 0.1 in outcome tables
Risk of bias
Item	Authors’ judgement	Description
Adequate sequence generation?	Unclear	Method of randomallocation not specified, but taken within strata based on clinic size and baseline smoking rates
Allocation concealment?	Unclear	Not specified.
Blinding? Women and clinical staff	Unclear	Educational intervention. Neither women nor providers would have been blind to the intervention
Incomplete outcome data addressed? All outcomes	No	One clinic excluded as did not report final data and some missing data for post-dissemination measures. No ITT of women dropping out of study. Only women completing study measures included in analysis
Free of selective reporting?	Yes	Smoking status and recall of intervention reported.
Free of detection bias?	Yes	Exhaled carbon monoxide >= 9.