Ref (type)	Population	Outcome, Interventions	Results and statistical analysis	Effect size	Favours
Retention in treatment
[13] Systematic review	1131 people 5 RCTs in this analysis	Proportion of people retained in treatment 2 to 52 weeks 340/564 (60%) with low-dose buprenorphine (2–4 mg) 224/567 (40%) with placebo	RR 1.50 95% CI 1.19 to 1.88 P = 0.00054	Small effect size	buprenorphine
[13] Systematic review	887 people 4 RCTs in this analysis	Proportion of people retained in treatment 2 to 52 weeks 281/430 (65%) with medium-dose buprenorphine (6–12 mg) 172/457 (38%) with placebo	RR 1.74 95% CI 1.06 to 2.87 P = 0.030	Small effect size	buprenorphine
[13] Systematic review	728 people 4 RCTs in this analysis	Proportion of people retained in treatment 2 to 52 weeks 227/362 (63%) with high-dose buprenorphine (16 mg) 150/366 (41%) with placebo	RR 1.74 95% CI 1.02 to 2.96 P = 0.042	Small effect size	buprenorphine