Schottenfield 2008.

Methods	randomised controlled trial double blind, double dummy
Participants	126 opioid dependent patients according to DSM IV. Mean age: 37 years; male percentage not reported
Interventions	group A naltrexone 50 mg/day plus buprenorphine placebo + drug counselling (n: 43) group B: buprenorphine 8mg/day plus naltrexone placebo plus drug counselling (n. 44) group C: buprenorphine placebo plus naltrexone placebo plus drug counselling (n. 39) length of study: 3 months
Outcomes	retention in treatment retention in treatment without relapsing days to first heroin use days to heroin relapse ( three consecutive urine positive tests o one positive followed by two consecutive mising tests
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Adequate sequence generation?	Low risk	quote: " a simple complete randomisation sequence was generated by a computer programme "
Allocation concealment?	Low risk	" the sequence was maintained in the USA and disclosed only to the study pharmacist in Malaysia for preparation of double blind, double dummy drugs "
Blinding? objective outcomes	Low risk	double blind, double dummy
Blinding? subjective outcomes	Low risk	double blind, double dummy
Incomplete outcome data addressed? All outcomes	Low risk	three patients withdrawn from the study, one from each group