Table 4.

GRADE Evidence Profile of Included Studies

Study	Number of biases for downgrading	Publication bias	Indirectness of evidence	Imprecision of confidence intervals	Inconsistency with other trials	Reasons for quality upgrading	Overall quality
Chan et al. (2009)	One	Undetected	Undetected	Undetected	Undetected	Large Effect Size	High
Dierick-van Daele et al. (2009)	Two	Undetected	Undetected	Undetected	Undetected	Undetected	Moderate
Kamps et al. (2003)	Three	Undetected	Undetected	Some imprecision	Undetected	Undetected	Low
Kinnersley et al. (2000)	One	Undetected	Undetected	Undetected	Undetected	Undetected	High
Krichbaum (2007)	Four	Undetected	Detected	Undetected	Undetected	Undetected	Very Low
Kuethe et al. (2011)	One	Undetected	Undetected	Undetected	Undetected	Large Effect Size	High
Mundinger et al. (2000)	Three	Undetected	Detected	Undetected	Undetected	Undetected	Low
Ndosi et al. (2014)	One	Undetected	Undetected	Some imprecision	Undetected	Undetected	Moderate
Ryden et al. (2000)	Three	Undetected	Undetected	Undetected	Undetected	Large Effect Size	Moderate
Stables et al. (2004)	One	Undetected	Undetected	Undetected	Undetected	Undetected	High
van Zuilen et al. (2011)	Two	Undetected	Undetected	Undetected	Undetected	Undetected	Moderate
Venning et al. (2000)	Three	Undetected	Undetected	Undetected	Undetected	Undetected	Low
Williams et al. (2005)	One	Undetected	Undetected	Undetected	Undetected	Large Effect Size	High