Table 3.

Risk of different types of biases in the included studies

	Barlow 1992[38]	Borkovec 1993[14]	Butler 1991[39]	Dugas 2003[25]	Dugas 2010[40]	Ladouceur 2000[41]	Linden 2005[42]	Mohlman 2013[43]	Stanley 1996[44]	Stanley 2003[45]	Wetherell 2003[46]	Zinbarg 2007[47]	kappab
Sequence generation	low	low	low	low	low	low	low	?	low	low	low	low	0.43
Allocation concealment	?	low	?	high	low	high	low	high	?	high	low	?	0.49
Blinding therapist	high	high	high	high	high	high	high	high	high	high	high	high	1.00
Blinding assessor	low	low	low	low	low	low	low	low	low	low	low	low	1.00
Blinding participant	high	high	high	high	high	high	high	high	high	high	high	high	1.00
Incomplete outcome data	low	low	high	low	low	low	low	low	low	low	low	low	0.63
Selective reporting	low	low	low	low	low	low	low	low	low	low	low	low	1.00
Researcher allegiance	low	low	low	low	low	?	low	low	low	low	low	low	1.00
Therapist allegiance	?	?	?	?	?	?	?	?	?	?	?	?	1.00
Therapist qualification	low	low	low	low	low	low	low	high	low	low	low	low	1.00
Treatment fidelity	low	low	low	low	low	low	low	low	low	low	low	low	1.00
Treatment integrity	low	low	low	low	low	low	low	low	low	low	low	low	1.00
Other risks of biasa	high	high	low	high	low	?	?	low	high	high	low	low	0.86
OVERALL RISK OF BIAS	high	high	high	high	low	high	low	high	high	high	low	low	0.64

^a including bias from patients who are lost to follow-up,use of medication,and co-morbid conditions

^b Kappa values for inter-rater reliability of the two independent coders who assessed each of the 13 items for the 12 studies