Woody 2008.

Methods	Multicentre randomised controlled trial. Recruitment modality described.
Participants	154 participants who met the DSM IV diagnostic criteria for opioid dependence and who sought outpatient treatment.152 randomised. Mean age: 19 years. Only one participant was 15 years old and no participants were 14 years old. Male: 59%. White: 56%.
Interventions	(1) Maintenance group:12 weeks buprenorphine. Naloxone: up to 24 mg/day buprenorphine and 0.5 mg naloxone for 9 weeks and then tapered to week 12. :74 patients. (2) Detoxification group: 2 weeks buprenorphine. Naloxone: up to 14 mg/day buprenorphine and then tapered to day 14: 78 patients. Both groups were offered 1 weekly individual and 1 group counselling.
Outcomes	Primary outcome: opioid positive urine test results at weeks 4, 8 and 12. Secondary outcomes: drop out, self‐reported use, enrolment in addiction treatment outside the assigned condition, other drug use, adverse events. Results at 6,9,12 months follow‐up: self‐reported opioid use, self‐reported other drug use, other addiction treatment received.
Notes	Country: USA Setting: outpatients
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Randomisation occurred through an automated 24‐hour service at the Veterans Affairs Cooperative Studies Program in Perry Point, Maryland, that was programmed to randomise patients separately by site. At each site, a biased coin randomisation protected against severe imbalance of sex, ethnicity, route of administration, and age across the treatment groups. Age was dichotomised as 14 to 18 years or 18 to 21 years, ethnicity as the majority ethnic group vs all others within the site, and route of administration as injecting or non injecting.
Allocation concealment (selection bias)	High risk	Balance was assessed by comparing the group sum of the binary indicators as each new patient was randomised. If both groups were balanced when a new patient was being randomised, then each group had an allocation probability of 1/2; if there was an imbalance, then the group with the higher score on the sum of indicators received an allocation probability of 1/3 and the other group a probability of 2/3.
Blinding (performance bias and detection bias) objective outcomes (drop out, use of substance measured by urine‐analysis, abstinent at follow‐up, initiation of naltrexone treatment)	Low risk	Patients and providers impossible to be blinded for the nature of the intervention (14 days detox vs 12 weeks maintenance). COMMENT: objective outcomes unlikely to be biased by lack of blinding.
Blinding (performance bias and detection bias) Subjective outcome	High risk	Patients and providers impossible to be blinded for the nature of the intervention (14 days detox vs 12 weeks maintenance) Outcome assessor not blinded: "Research assistant likely knew groups assignment because the study was not blinded"
Incomplete outcome data (attrition bias) All outcomes	Low risk	Number of participants withdrawn from the study reported for each group. Reason for withdrawal given. Analysis on the basis of the Intention‐to‐treat principle: "patients were contacted at all assessment point regardless of whether they remained in treatment".
Selective reporting (reporting bias)	Low risk

DSM IV: Diagnostic and Statistical Manual of Mental Disorders, 4th edition
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