Ref (type)	Population	Outcome, Interventions	Results and statistical analysis	Effect size	Favours
Proportion of people completing treatment
[33] Systematic review	168 people 4 RCTs in this analysis	Proportion completing treatment 52/85 (61%) with buprenorphine 43/83 (52%) with methadone	RR 1.18 95% CI 0.93 to 1.49 P = 0.18		Not significant
[32] Systematic review	96 people 3 RCTs in this analysis	Completion of treatment 31/54 (57%) with buprenorphine 30/42 (71%) with methadone	OR 0.92 95% CI 0.03 to 29.30		Not significant