Table 2.

Quality assessment of studies included in meta-analysis

Study/Year	Clear inclusion and exclusion criteria	Document the loss to follow up rate	Clear definition of outcome	Sufficient duration follow-up (>5 years)	Control of confounding	Appropriate statistics	Total points
Muntner et al [8] 2002	Yes	Yes	Yes	Yes	Yes	Yes	6
Hillege et al [9] 2002	Yes	Yes	No	No	Yes	Yes	4
Romundstad et al [12] 2003	Yes	Yes	Yes	No	Yes	Yes	5
Yuyun et al [2] 2004	Yes	unclear	Yes	Yes	Yes	Yes	5
Wang et al [3] 2005	Yes	Yes	Yes	Yes	Yes	Yes	6
Cao et al [6] 2008	Yes	unclear	Yes	Yes	Yes	Yes	5
Jassal et al [11] 2008	Yes	Yes	Yes	Yes	No	Yes	6
Scheven et al [7] 2013	Yes	Yes	Yes	Yes	Yes	Yes	6