Table 6. Risk of bias in the individual studies included in the review.

first author (year)	randomi-zation?	allocation concealed?	patient blinding?	care provider blinding?	outcome assessor blinding?	drop-outs described & accepatble?	ITT-analysis?	free of suggestion of selective outcome reporting?	groups similar at baseline?*	co-interventions avoided or similar?	acceptable compliance?	similar timing outcome assessment?	yes-score
Andersson (1999)	yes	yes	no	no	no	no	no	yes	yes	yes	yes	yes	7
Licciardone (2003)	yes	yes	U	no	U	yes	U	no	yes	yes	U	yes	6
UK BEAM (2004)	yes	yes	no	no	no	yes	no	yes	yes	yes	yes	yes	8
McReynolds (2005)	yes	yes	no	no	no	yes	U	yes	yes	yes	NA**	yes	7
Peters (2006)	yes	yes	no	no	no	yes	no	yes	yes	yes	yes	yes	8
Heinze (2006)	yes	yes	no	no	no	yes	yes	yes	no	yes	yes	yes	8
Chown (2008)	yes	yes	U	no	U	yes	U	yes	yes	yes	yes	yes	8
Recknagel (2008)	yes	yes	no	no	no	yes	yes	yes	yes	yes	yes	yes	9
Schwerla (2008)	yes	yes	no	no	no	yes	no	yes	yes	yes	U	yes	7
Engemann (2009)	yes	yes	no	no	no	yes	yes	yes	yes	yes	U	yes	8
Licciardone (2010)	yes	U	no	no	no	no	yes	yes	yes	yes	yes	yes	7
Cruser (2012)	yes	yes	no	no	no	yes	yes	yes	yes	yes	yes	yes	9
Vismara (2012)	yes	yes	no	no	no	yes	no	yes	yes	yes	yes	yes	8
Licciardone (2013a)	yes	yes	U	no	U	yes	no	no	yes	yes	U	yes	6
Licciardone (2013b)	yes	yes	U	no	U	yes	yes	no	yes	yes	yes	yes	8
Belz (2015)	yes	yes	no	no	no	yes	yes	yes	yes	yes	U	yes	8
Hensel (2015)	yes	yes	no	no	no	no	yes	yes	no	yes	no	yes	6
Schwerla (2015)	yes	yes	U	no	no	yes	yes	yes	no	yes	U	yes	7
Licciardone (2016)	yes	yes	U	no	U	yes	yes	yes	yes	yes	yes	yes	9

*this criterion was scored ‘no’ if a significant between-group difference for at least one variable was present

**single-session intervention

ITT, intention-to-treat; NA, not applicable; U, unsure