Table 2 Newcastle-Ottawa Scale (NOS) risk of bias assessment of the included studies
Author, year | Selection (0–4) | Comparability (0–2) | Exposure/outcome (0–3) | Total score (0–9) |
|---|---|---|---|---|
Torosian 2000 [42] | 3 | 1 | 2 | 6 |
Sponseller 2000 [41] | 2 | 2 | 3 | 7 |
Frischhut 2000 [12] | 3 | 0 | 3 | 6 |
Parsch 2001 [13] | 3 | 0 | 2 | 5 |
Crawford 2003 [20] | 3 | 0 | 3 | 6 |
Ozerdemoglu 2003 [43] | 4 | 0 | 3 | 7 |
Ulsenheimer 2004 [44] | 3 | 0 | 3 | 6 |
Erol 2005 [26] | 3 | 0 | 3 | 6 |
Lemelle 2006 [45] | 4 | 0 | 3 | 7 |
Gerlach 2009 [46] | 4 | 2 | 3 | 9 |
Huang 2010 [49] | 3 | 0 | 3 | 6 |
Akbar 2010 [48] | 4 | 0 | 3 | 7 |
Akbar 2010 [47] | 3 | 0 | 3 | 6 |
Yildirim 2015 [14] | 4 | 1 | 3 | 8 |
Wang 2015 [50] | 4 | 2 | 3 | 9 |
Januschek 2016 [53] | 3 | 0 | 2 | 5 |
Altiok 2016 [51] | 3 | 0 | 3 | 6 |
El-Fadl 2016 [52] | 3 | 0 | 3 | 6 |
Matar 2017 [54] | 3 | 0 | 3 | 6 |
Ryabykh 2018 [21] | 3 | 0 | 3 | 6 |
Spazzapan 2018 [56] | 3 | 0 | 3 | 6 |
North 2018 [55] | 4 | 0 | 3 | 7 |
Beuriat 2018 [9] | 3 | 0 | 3 | 6 |
Goldstein 2019 [10] | 4 | 1 | 3 | 8 |
Sileo 2019 [57] | 3 | 0 | 3 | 6 |
Beuriat 2019 [11] | 4 | 0 | 3 | 7 |