Table 4.

Results From Subgroup Analyses of Several Possible Moderating Variables With Contingency Management Outcomes up to 1 Year Following Treatment

Moderator (k)	OR	95% CI	Q	p
Control condition (24)			2.79	.25
Nonspecific therapy (9)	1.15	[0.90, 1.48]
Community-based comprehensive therapy (12)	1.40	[1.07, 1.83]
Protocol-focused specific therapy (3)	0.91	[0.58, 1.43]
Escalating reinforcers (24)			0.00	.95
No (3)	1.21	[0.74, 1.97]
Yes (21)	1.23	[1.02, 1.48]
Fading reinforcers (24)			0.15	.70
No (18)	1.24	[1.03, 1.51]
Yes (6)	1.14	[0.78, 1.67]
Immediate reinforcers (32)			1.03	.31
No (5)	1.00	[0.69, 1.46]
Yes (27)	1.24	[1.05, 1.48]
Outcome type (24)			2.57	.11
Percentage of negative samples (10)	1.49	[1.08, 2.06]
Point prevalence (14)	1.10	[0.93, 1.31]
Study recruitment at a methadone treatment clinic (24)			1.19	.28
No (15)	1.16	[0.97, 1.38]
Yes (9)	1.46	[1.00,2.11]
Study quality (24)			2.45	.12
High (13)	1.08	[0.88, 1.33]
Low (11)	1.41	[1.08, 1.84]
Time of follow-up in weeks (24)			0.40	.52
<3 months (6)	1.37	[0.93, 2.00]
3 to 12 months (18)	1.19	[0.98, 1.44]
Type of drug (24)			0.06	.97
Opioids (1)	1.34	[0.63, 2.84]
Stimulants (15)	1.22	[0.98, 1.51]
Polysubstance use (8)	1.22	[0.89, 1.67]
Type of reinforcer (32)			0.40	.53
Prize (17)	1.16	[0.98, 1.38]
Voucher (15)	1.29	[0.97, 1.73]

Note. k = number of studies; OR = odds ratio; CI = confidence interval.