Comparison 1. Antagonist‐induced vs conventional.

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 Number refusing group allocation or failing to attend	3	240	Risk Ratio (M‐H, Random, 95% CI)	0.51 [0.15, 1.68]
2 Number completing detoxification	2		Risk Ratio (M‐H, Fixed, 95% CI)	Subtotals only
2.1 Methadone comparison	1	30	Risk Ratio (M‐H, Fixed, 95% CI)	1.82 [1.14, 2.91]
2.2 Clonidine comparison	1	70	Risk Ratio (M‐H, Fixed, 95% CI)	1.26 [0.92, 1.73]
3 Number commencing naltrexone maintenance treatment	3		Risk Ratio (M‐H, Fixed, 95% CI)	Subtotals only
3.1 Clonidine comparison	3	240	Risk Ratio (M‐H, Fixed, 95% CI)	4.28 [2.91, 6.30]
3.2 Buprenorphine comparison	1	72	Risk Ratio (M‐H, Fixed, 95% CI)	1.29 [1.04, 1.60]
4 Retained in naltrexone maintenance treatment or abstinent at 12 weeks	4		Risk Ratio (M‐H, Fixed, 95% CI)	Subtotals only
4.1 Tapered methadone comparison	1	30	Risk Ratio (M‐H, Fixed, 95% CI)	2.0 [0.90, 4.45]
4.2 Clonidine comparison	3	240	Risk Ratio (M‐H, Fixed, 95% CI)	2.77 [1.37, 5.61]
4.3 Buprenorphine comparison	1	72	Risk Ratio (M‐H, Fixed, 95% CI)	0.82 [0.34, 1.97]