Strecher 2000.

Methods	Randomised controlled trial of computer‐generated messages to support women to stop smoking in pregnancy. Study conducted in 2 university hospitals in North Carolina and Michigan (USA), with recruitment from December 1996 to December 1997.
Participants	Inclusion criteria: Women who have "smoked 100 cigarettes in their lifetime and still smoking" or "had quit since becoming pregnant". Exclusion criteria: Not further specified. Recruitment: Unclear how many women screened during first prenatal visit. using a self‐administered computer screening program. 173 women randomised (C = 85, I = 88). Baseline characteristics: Mean cigarettes per day before pregnancy: C = 18.7, I = 20.3; current mean cigarettes per day: C = 11.8, I = 12.9; Mean cotinine: C = 2597, I = 2701; Mean smokers in household: C = 1.1, I = 1.0. Mean age: C = 26.6, I = 25.5; Mean education: C = 12.5, I = 12.5; White: C = 81.2%, I = 87.4%. Progress + coding: None.
Interventions	Control: Received "a pregnant woman's guide to quit smoking" at the first visit. Intervention: Entered personal data into a hand‐held computer at AN visits, which subsequently generated personalised tailored messages, which were posted to the woman. Main intervention strategy: Health education (single intervention) compared to less intensive intervention. Intensity: Frequency (C = I, I = 6), Duration (C = 1, I = 2). Unclear if intervention provided by dedicated project or existing staff as technological intervention.
Outcomes	Biochemically validated smoking cessation at 6 weeks postpartum* (0‐5 months pp). Biochemically validated cessation at 24/40 gestation ('mid‐term') and self‐reported cessation 3 months postpartum but outcomes not reported. Mean cigarettes per day and cotinine concentrations collected and reported as 'not significant' but actual figures not reported. Participant evaluation of using hand‐held computers and reactions to computerised materials.
Notes	Numbers in paper inconsistent: I = 88, C = 85 in methods section, I = 104, C = 87 in results section. No justification for change of denominators.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	By computer algorithm.
Allocation concealment (selection bias)	Unclear risk	Not described.
Incomplete outcome data (attrition bias) All outcomes	High risk	Outcome data (C = 87, I = 104) are inconsistent with figures reported as randomised in methods and baseline data table (C = 85, I = 88). If comparing outcome data using ITT and excluding those 'lost to follow‐up' it appears that more than 30% of the control group (30/87) were lost to follow‐up. In this review we have used the ITT data (C = 87, I = 104) as the denominator.
Selective reporting (reporting bias)	High risk	Results are conflicting and actual figures for pregnancy (24/40) are not reported, nor are figures for mean cigarettes per day or cotinine concentrations.
Other bias	Low risk	No other bias detected.
Biochemical validation of smoking abstinence (detection bias)	Low risk	Urinary cotinine analysis at 24 weeks' gestation and at 6 weeks postpartum (cut‐off < 80 ng/mL).
Blinding of participants and personnel (performance bias) All outcomes	High risk	Participants and personnel not blinded to intervention.
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Not reported.
Incomplete implementation	Unclear risk	Process evaluation not reported.
Equal baseline characteristics in study arms	Low risk	Baseline comparisons revealed no significant differences in age, race, education, number of cigarettes smoked before pregnancy, and baseline stage of change.
Contamination of control group	Low risk	Technological intervention so contamination unlikely.