Lintzeris 2004.

Methods	Two‐group, open‐label, randomised clinical trial, with participants block‐randomised and allocated to treatment group by an independent agency. Separate randomisation schedules were used for participants in methadone maintenance and heroin users seeking treatment.
Participants	Geographic region: Australia (3 sites). N = 158. Mean age: 32 years (heroin intake), 29 years (methadone intake). 57.6% male. Inclusion criteria: diagnosis of heroin dependence, or in methadone maintenance treatment for 8 weeks or less and able to reduce to 60 mg of methadone (to allow randomisation to ongoing methadone treatment or to buprenorphine). Exclusion criteria: under 18 years of age, pregnant and/or breast‐feeding.
Interventions	26 weeks of maintenance, flexible dosing. Buprenorphine (sublingual tablets) mean dose 14.5 mg. Methadone mean dose 51.2 mg (methadone intake), 49.4 mg (heroin intake).
Outcomes	Retention in treatment and self‐reported heroin use.
Funding source	None reported.
Declarations of interest	None reported.
Notes	Clinicians were advised to exercise caution but not necessarily exclude participants with concomitant medical or psychiatric conditions.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	"Randomised" ‐ method not specified.
Allocation concealment (selection bias)	Low risk	"Subjects were (block) randomised and allocated by an independent agency".
Blinding (performance bias and detection bias) All outcomes	Low risk	Open‐label. Objective outcome measurement not influenced by lack of blinding.
Incomplete outcome data (attrition bias) All outcomes	Low risk	Intention‐to‐treat.