Harris 2015.

Methods	A 2‐armed single randomised controlled trial of a web‐based contingency management program; Motiv8. This study was conducted in Rural Appalachia, Ohio and Kentucky on a community sample of pregnant smokers, recruited from prenatal clinics.
Participants	Inclusion criteria: Adults aged 18 years and older, daily smokers (reporting smoking at least 2 cigarettes per day verified by breath CO readings and urinary cotinine levels), and were <= 12 weeks pregnant Exclusion criteria: Not stated. Recruitment: 47% participation rate (C = 10 I = 7). Baseline characteristics: Nicotine dependence (modified Fagerstroms test) (C = 4.90 I = 5.71), Cigarettes per day (C = 13.69 I = 9.45) Mean Age (C = 24.20 I = 24.00). Progress + coding: Low SES.
Interventions	Control: Intensive phone delivered cessation counselling program based on Smoking Cessation for Healthy Births (SCHB). Intervention: The Motiv8 program lasted 6 weeks and consisted of 5 phases: Baseline (7 days), Shaping (4 days), Abstinence (21 days), Thinning (5 days), and Return to Baseline (5 days). During each phase, participants submitted video recordings of themselves twice per day (at least 8 hours apart) giving breath samples using the Smokerlyzer. They could earn vouchers exchangeable for online purchases with major retailers (e.g. Best Buy, Wal‐Mart) for criterion breath samples based on program phase. For the Abstinence phase, participants were required to have breath CO levels <= 4 ppm. Main Intervention strategy: Incentives (single) v alternative Intervention Intensity: Frequency (C = 4, I = 6) Duration (C = 4, I = 4). Intervention provided by study staff: efficacy study
Outcomes	Biochemically validated smoking abstinence in late pregnancy*, Smoking reduction by 50% urine cotinine levels*
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Reporting smoking at least 2 cigarettes per day verified by breath CO readings and urinary cotinine levels
Allocation concealment (selection bias)	Low risk	As randomisation was done by computer, allocation of participant to control or intervention would have been concealed.
Incomplete outcome data (attrition bias) All outcomes	Low risk	Any missing data were coded as non abstinent/reduction.
Selective reporting (reporting bias)	Low risk	All outcomes are reported.
Other bias	Low risk	No other bias detected.
Biochemical validation of smoking abstinence (detection bias)	Low risk	Smoking was biochemically validated by breath CO levels <= 4 ppm and urinary cotinine levels.
Blinding of participants and personnel (performance bias) All outcomes	High risk	Blinding did not seem to occur as physician and participant would know which arm of the trial they were in.
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	This was not described.
Incomplete implementation	High risk	Only 68% of intervention participants provided the required breath samples at follow‐up and in control, phone counsellors provided on average 3.9 of the required 5 phone calls.
Equal baseline characteristics in study arms	Low risk	Baseline characteristics in both arms appear equal.
Contamination of control group	Low risk	Intervention and control were either delivered via the web or mobile phone so contamination very unlikely.