Table 2 Risk of bias for cohort trails
Study | Selection | Comparability | outcome | Score | |||||
|---|---|---|---|---|---|---|---|---|---|
Represent-ativeness of the exposed cohort | Selection of the non-exposed cohort | Ascertainment of exposure | Demonstration that outcome of interest was not present at start of study | Comparabili-ty of Cohorts on the Basis of the Design or Analysis | Assess-ment of outco-me | Was follow-up long enough for outcomes to occur | Adequacy of follow -up of cohorts | ||
Beloosesky 2002 [26] | ★ | ★ | ★ | ★ | ★ | ★ | 6 | ||
Bliemel 2015 [27] | ★ | ★ | ★ | ★ | ★ | ★ | ★ | ★ | 8 |
Brouquet 2010 [25] | ★ | ★ | ★ | ★ | ★ | ★ | ★ | 7 | |
Guo 2014 [29] | ★ | ★ | ★ | ★ | ★ | ★ | ★ | ★ | 8 |
Häkkinen 2007 [28] | ★ | ★ | ★ | ★ | ★ | ★ | ★ | ★ | 8 |
Huusko 2000 [19] | ★ | ★ | ★ | ★ | ★ | ★ | ★ | ★ | 8 |
Jones 2017 [31] | ★ | ★ | ★ | ★ | ★ | ★ | ★ | 7 | |
Kalisvaart 2006 [30] | ★ | ★ | ★ | ★ | ★ | ★ | 6 | ||
Karni 2013 [33] | ★ | ★ | ★ | ★ | ★ | ★ | ★ | 7 | |
Kratz 2015 [32] | ★ | ★ | ★ | ★ | ★ | ★ | 6 | ||
Lee 2016 [7] | ★ | ★ | ★ | ★ | ★ | ★ | ★ | 7 | |
Moncada 2005 [35] | ★ | ★ | ★ | ★ | ★ | ★ | ★ | 7 | |
Morghen 2011 [34] | ★ | ★ | ★ | ★ | ★ | ★ | ★ | ★ | 8 |
Osse 2012 [36] | ★ | ★ | ★ | ★ | ★ | ★ | ★ | 7 | |
Otano 2015 [38] | ★ | ★ | ★ | ★ | ★ | ★ | ★ | ★ | 8 |
Reissmüller 2006 [37] | ★ | ★ | ★ | ★ | ★ | ★ | ★ | 7 | |
Rolland 2004 [22] | ★ | ★ | ★ | ★ | ★ | ★ | ★ | ★ | 8 |
Ruggiero 2016 [21] | ★ | ★ | ★ | ★ | ★ | ★ | ★ | 7 | |
Schaller2012 [23] | ★ | ★ | ★ | ★ | ★ | ★ | ★ | ★ | 8 |
Witlox 2009 [24] | ★ | ★ | ★ | ★ | ★ | ★ | ★ | 7 | |
Yukako 2016 [20] | ★ | ★ | ★ | ★ | ★ | ★ | 6 | ||