Table 4.

Quality assessment of non-randomized controlled trials

	Selection					Outcome
Study	Representativeness of the exposed cohort	Selection of the non exposed cohort	Ascertainment of exposure	Outcome(s) absent at start of study	Comparability of cohorts	Assessment of outcome	Adequate follow up time	Adequacy of follow up
Alabaz 2000 [10]	*	*	*	*		*	*	*
Allesandroni 2010 [11]	*		*	*	*	*	*	*
Bemelman 2000 [12]	*		*	*	*	*	*	*
Benoist 2003 [13]	*		*	*	**	*	*	*
Bergamaschi 2003 [14]	*		*	*	*	*	*	*
Broquet 2010 [15]	*	*	*	*	*	*	*	*
Courtney 2011 [16]	*		*	*		*	*	*
da Luz Moreira 2007 [17]	*	*	*	*	**	*		*
Diamond 2001 [18]	*	*	*	*	*	*	*	*
Duepree 2002 [19]	*	*	*	*		*	*	*
Dunker 1998 [20]		*	*	*		*	*	*
El Gazaaz 2010 [21]	*	*	*	*	**	*	*	*
Eshuis 2008 [22]	*	*	*	*	*	*	*	*
Fichera 2007 [24]	*	*	*	*		*		*
Huilgol 2004 [25]	*		*	*		*	*	*
Kishi 2000 [26]	*	*	*	*		*	*	*
Lauro 2004 [27]	*	*	*	*	*	*	*	*
Lowney 2006 [28]			*	*	*	*	*	*
Luan 2000 [29]			*	*		*	*	*
Msika 2001 [32]	*	*	*	*	*	*	*	*
Nakajima 2010 [33]	*	*	*	*		*	*	*
Shore 2003 [34]		*	*	*	*	*	*	*
Sica 2008 [35]	*	*	*	*	*	*	*	*
Tabet 2001 [37]	*	*	*	*	*	*	*	*
Tanaka 2008 [38]	*	*	*	*	*	*		*
Thaler 2005 [39]		*	*	*	*	*	*	*
Uchikoshi 2004 [40]			*	*	*	*	*	*
Umanskiy 2010 [41]	*	*	*	*	*	*		*
Von Allmen 2003 [42]	*	*	*	*	*	*	*	*
Wu 1997 [43]	*	*	*	*		*	*	*

A study can be awarded a maximum of 1 star (*) in each of the selection and outcome categories, and a maximum of 2 stars (**) in thecomparability section.