Table 2 The assessment of the risk of bias in each cohort study using the Newcastle-Ottawa scale
Study | Selection (0–4) | Comparability (0–2) | Outcome (0–3) | Total | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
REC | SNEC | AE | DO | SC | AF | AO | FU | AFU | ||
Barbazan 2014 [30] | 0 | 1 | 1 | 1 | 0 | 0 | 1 | 1 | 0 | 5 |
Kuboki 2013 [34] | 0 | 1 | 1 | 1 | 0 | 0 | 1 | 0 | 0 | 4 |
Lu 2013 [36] | 1 | 1 | 1 | 1 | 0 | 0 | 1 | 1 | 1 | 7 |
Iinuma 2013 [35] | 1 | 1 | 1 | 1 | 0 | 0 | 1 | 1 | 0 | 6 |
Sastre 2012 [26] | 1 | 1 | 1 | 1 | 0 | 0 | 1 | 1 | 0 | 6 |
de Albuquerque 2012 [27] | 0 | 1 | 1 | 1 | 0 | 0 | 1 | 0 | 1 | 5 |
Matsusaka 2011 [28] | 0 | 1 | 1 | 1 | 1 | 0 | 1 | 1 | 0 | 6 |
Konigsberg 2010 [33] | 0 | 1 | 1 | 1 | 0 | 0 | 1 | 0 | 0 | 4 |
Yalcin 2010 [32] | 0 | 1 | 1 | 1 | 0 | 0 | 1 | 0 | 0 | 4 |
Tol 2010 [29] | 1 | 1 | 1 | 1 | 0 | 0 | 1 | 1 | 0 | 6 |
Yen 2009 [37] | 1 | 1 | 1 | 1 | 0 | 0 | 1 | 1 | 0 | 6 |
Cohen2008 [11] | 0 | 1 | 1 | 1 | 0 | 0 | 1 | 1 | 0 | 5 |
Staritz 2004 [31] | 0 | 1 | 1 | 1 | 0 | 0 | 1 | 0 | 1 | 5 |