Table 2 Summary of quality assessment for cohort studies

Braaten et al., 2005 [22]

*

*

⋅⋅⋅

*

*

*

*

*

⋅⋅⋅

7

Brummett et al., 2011 [38]

*

*

⋅⋅⋅

⋅⋅⋅

*

*

⋅⋅⋅

*

⋅⋅⋅

5

Chaix et al., 2010 [39]

*

*

⋅⋅⋅

*

*

*

*

⋅⋅⋅

⋅⋅⋅

6

Dyer et al., 1999 [40]

*

*

*

*

*

*

*

*

*

8

Heck & Palmuck, 2007 [23]

*

*

*

*

*

*

*

*

⋅⋅⋅

8

Joshi et al., 2008 [30]

⋅⋅⋅

*

⋅⋅⋅

*

*

*

*

*

*

7

Kivimaki et al., 2009 [32]

*

*

⋅⋅⋅

*

*

*

*

*

⋅⋅⋅

7

Kuper et al., 2007 [33]

*

*

⋅⋅⋅

*

*

*

*

*

*

8

Laaksonen et al., 2007 [34]

*

*

⋅⋅⋅

⋅⋅⋅

*

*

*

*

*

7

Larsen et al., 2011 [26]

*

⋅⋅⋅

*

*

*

*

*

*

*

7

McFadden et al., 2009 [35]

*

*

*

*

*

*

*

*

⋅⋅⋅

9

Melchior et al., 2005 [28]

⋅⋅⋅

*

⋅⋅⋅

*

*

*

*

*

⋅⋅⋅

6

Sundell et al., 2008 [36]

*

*

⋅⋅⋅

*

*

*

*

*

*

8

Veronesi et al., 2010 [37]

*

*

*

*

*

*

*

*

⋅⋅⋅

8