Table 2.

Summary of the findings from the selected studies (n = 16).

Reference number of the study/studies	Type of TC	Comparison condition	Followup length	Outcome measures
				Retention	Substance use	Criminal activity	Employment	Health	Family and social relations
(1) Sacks et al., 2012 [19]	Prison	TAU	1 year			+
(2) Zhang et al., 2011 [44]	Prison	TAU	1 year			=
			5 years			=
(3) Messina et al., 2010 [45]	Prison	Other TC	1 year	+	=	=		=	=
(4) Welsh, 2007 [37]	Prison	TAU	2 years		=	+	+
(5) Sullivan et al., 2007 [46]	Prison	TAU	1 year		+	+
(6) Morral et al., 2004 [47]	Prison	TAU	1 year	=	+	=		+
(7) Inciardi et al., 2004 [28]	Prison	TAU	6 months		+	+		+
			1 year		+	+
			3 years		+	=
			3 years 6 months		+	+
			5 years		+	+
(8) Prendergast et al., 2004 [33]	Prison	TAU	1 year		+	+
			2 years			+
			5 years	=	=	+	=	=
(9) Greenwood et al., 2001 [25]	Community-based	Other TC	6 months	=	+			+	+
			1 year	=	=			+
			1 year 6 months		=			+	+
(10) Nemes et al., 1999 [42]	Community-based	Other TC	1 year 6 months	=	+	+	+
(11) De Leon et al., 2000 [24]	Community-based	TAU	1 year		+	=	+	=
			2 years		+ =	+	+ =	+
(12) Nuttbrock et al., 1998 [38]	Community-based	TAU	1 year	−	+			+
(13) McCusker et al., 1997 [51]	Community-based	Other TC	6 months	=	=
			1 year	−	=	=	+
(14) Hartmann et al., 1997 [43]	Prison	TAU	6 months		=	+
(15) Bale et al., 1984 [39]	Community-based	TAU	1 year	−	+	+	+	+
			2 years	+	+ (illicit) − (alcohol)	+	+
(16) Coombs et al., 1981 [41]	Community-based	Other TC	1 year	=	+

TC: Therapeutic Community, Other TC: Other TC modality, TAU: Treatment As Usual.