2. Study quality (summary).

Study	Selection bias	Patients blinding	Caregiver blinding	Attrition bias	Detection bias	Overall incl. perfor	Overall excl. perfor
Aswell 2006	+	‐	‐	+	unknown	C	B
De Leeuw 2005	unknown	‐	‐	+	unknown	C	B
Francis 1986	unknown	‐	‐	unknown	unknown	C	B
Fulcher 2005	unknown	‐	+	+	unknown	C	B
Hermansen 2001	‐ (blocks of 4)	‐	‐	‐	+	C	C
Hermansen 2004	+	‐	‐	+	unknown	C	B
Home 2004	+	‐	‐	+	unknown	C	B
Home 2005	+	‐	‐	unknown	unknown	C	B
Kolendorf 2006	unknown	‐	‐	unknown	unknown	C	B
Murphy 2003	unknown	‐	‐	‐	unknown	C	C
Pieber 2000	unknown	‐	‐	‐	unknown	C	C
Porcellati 2004	+	‐	‐	‐	unknown	C	C
Raskin 2000	+	‐	‐	unknown	unknown	C	B
Ratner 2000	unknown	‐	‐	+	unknown	C	B
Rosenstock 2000	unknown	‐	‐	unknown	unknown	C	B
Russel‐Jones 2004	unknown	‐	‐	+	unknown	C	B
Schober 2001	unknown	‐	‐	‐	unknown	C	C
Tunbridge 1989	+	+	+	+	unknown	B	B
Zinman 1999	unknown	+	+	+	unknown	B	B
Chatterjee 2007	+	‐	‐	‐	unknown	C	C
Robertson 2007	+	‐	‐	+	unknown	C	B
Rossetti 2003	unknown	‐	‐	‐	unknown	C	C
Vague 2003	+	‐	‐	+	unknown	C	B