Haug 2004.

Methods	RCT. Groups significantly different for race. No difference in drug use and psychiatric comorbidity.
Participants	77 pregnant opioid‐dependent women randomized with 14 disqualified post‐randomization, ≤ 26 weeks gestational age, receiving MMT and ≥5 cigarettes/day. Mean age 29.7; 84% African American; 79% single or never married; 97% unemployed; 94% less than high school education. DSM‐III‐R: all heroin dependent (100%), 41 (35%) cocaine dependent, 10 (16%) marijuana dependent, 17 (27%) alcohol dependent, all (100%) nicotine dependent. Exclusion criteria: not stated.
Interventions	For all MMT, no information on urine monitoring, or counselling/therapy. All received USD 10 voucher after initial battery and USD20 when 10‐week interview completed. Mean MMT dose 65.2 mg. All received PNC and substance abuse counselling ‐ no details described. Four MET sessions using a modification of the Project MATCH MET manual (Miller et al., 1995). Visit 1 ‐ rapport building; visit 2 (1 week later) ‐ personalized feedback on positive behaviours, negative consequences of smoking, and stage of change; visit 3 (week 4) ‐ commitment and plan for change developed; visit 4 (week 6) ‐ barriers to long‐term change addressed (n = 30 post disqualification). Standard care advice (no specific details related to content provided) (n = 33 post disqualification). Duration 10 weeks.
Outcomes	Retention in treatment as % attrition. Stage of change and stage movement. Urine toxicology done at the 10‐week follow‐up.
Notes	Randomization occurred during residential treatment. 14 disqualified post randomization for spontaneous abortion. 21 excluded for reasons not stated. We received raw data for urine toxicology after contacting the trial authors for information.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	"Seven women refused study participation and 77 patients completed baseline assessment and were randomized". No specific methods for randomization outlined.
Allocation concealment (selection bias)	Unclear risk	Allocation concealment not described.
Incomplete outcome data (attrition bias) All outcomes	High risk	"At the 10‐week follow‐up, participant attrition was 14% (n = 9), with missing participants evenly distributed between the MET (n = 4) and SC (n = 5) groups. The only difference between completers and those lost at follow‐up was average methadone dose during treatment (M=50.8mg vs. 36.3 mg, respectively), t(61)=‐6.34,p<.0001." Some information was provided related to attrition (total number of individuals who dropped out). Outcome measures did not explicitly state the number of participants analyses were based on. Furthermore, details were not provided related to which groups the initially disqualified participants came from, making attrition data more unclear.
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	No mention of blinding of outcome assessors.