Parker 2007 (AvC).

Methods	3‐armed randomised controlled trial aimed to evaluate the feasibility, cost and effectiveness of a telephone counselling intervention to support women to stop smoking in pregnancy. Study conducted at 22 urban prenatal care clinics in Rhode Island (Connecticut) and Massachusetts (USA). Study period not reported.
Participants	Inclusion criteria: Pregnant women who had smoked at least 1 puff of a cigarette within the past 30 days, no more than 26 weeks pregnant, had access to a telephone where she could be reached, and speak English or Spanish. Exclusion criteria: Not further specified. Recruitment: 8526 pregnant women were assessed at their first or second visit. 1065/1582 eligible women (67%) agreed to participate and were randomly assigned to 3 conditions (C (self‐help materials) =378; I1 (Self‐help materials + quit and win contest) = 329; I2 (self‐help materials + quit and win contest + MI counselling calls = 358). Baseline characteristics: Stratified by participation in calls: Mean cigarettes per day at baseline: 7.9 (6.3) to 8.7 (5.8). Baseline cotinine: 869 to 1239 ng/mL. Majority white, 40% <= 11 years education. Progress + coding: Low SES as 80% Medicaid recipients.
Interventions	A: Control: Participants received self‐help materials, which included a quit kit (A Smoker’s Guide to Quit Smoking) and a video (Commit to Quit), which had been shown to be effective in significantly reducing exposure or assisting pregnant women to quit smoking (SCRIPT trials). B: Intervention 1: Received the quit kit and were enrolled in a ‘‘Quit and Win’’ (Q&W) monetary incentive lottery program. Eligibility for the prize (US$100) was restricted to smokers who reported abstinence for at least 30 days and had their report confirmed by urinary cotinine. C: Intervention 2: Received the quit kit, the Q&W program, and up to 3 MI telephone calls. This study ID compares the control group (arm A) and Intervention 2 (arm C). Main intervention strategy: Counselling (multiple intervention) compared to a less intensive intervention. Intensity: Frequency (C = 1, I = 4), Duration (C = 1, I = 3). Intervention provided by dedicated project staff: Efficacy study.
Outcomes	Self‐reported smoking cessation biochemically validated with urinary cotinine (< 80 ng/mL) at 32 weeks' gestation (late pregnancy)*, 6 weeks and 6 months postpartum (outcomes not reported). Cost‐effectiveness analysis. Outcome data from conference abstract with all 3 arms and 89% valid cotinine assessments used in this analysis, as outcome data for arms A and B in main report are unclear.
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Not reported.
Allocation concealment (selection bias)	Unclear risk	Not reported.
Incomplete outcome data (attrition bias) All outcomes	Low risk	Attrition: C = 101/378 (27%), I = 118/358 (33%) by 6 months postpartum (reasons not reported). All randomised women included in analysis.
Selective reporting (reporting bias)	High risk	Smoking cessation at 6 weeks and 6 months postpartum not reported.
Other bias	Low risk	No other bias detected.
Biochemical validation of smoking abstinence (detection bias)	Unclear risk	Biochemical validation of self‐reported smoking status using urinary cotinine (< 80 ng/mL). Conference report states only 219/245 self‐reported quitters had biochemically confirmed smoking status, and 17.2% required reclassification. Pg 1045 states "Samples were obtained from 114 women during the first prenatal visit, from 113 during the third trimester, and 23 during the 6 month postpartum visit. We were unable to contact the remainder of the women, and therefore did not have samples to confirm their self‐reported smoking status".
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Not feasible for participants and personnel to be blinded to educational intervention.
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Not reported.
Incomplete implementation	High risk	Process evaluation showed researchers were unable to reach 14%, 86% received 1 call, 60% 2 calls and 46% 3 calls.
Equal baseline characteristics in study arms	Low risk	The absence of significant differences for multiple salient predictors and other weaker predictors of smoking behaviour change strongly suggested that the call groups were comparable at baseline.
Contamination of control group	Low risk	Specific counsellors providing intervention so low risk of contamination.