Table 2 Quality ratings for the studies included on the basis of Newcastle-Ottawa quality assessment scale (n = 9)
First author, year | Selection | Comparability | Outcome | Total score |
|---|---|---|---|---|
Braga, 2006 [15] | 3 | 1 | 2 | 6 |
Ergün, 2010 [18] | 3 | 2 | 2 | 7 |
Duru, 2012 [19] | 3 | 2 | 2 | 7 |
Oztürk, 2012 [20] | 4 | 2 | 2 | 8 |
Traxdorf, 2016 [21] | 3 | 1 | 2 | 6 |
Riad, 2017 [22] | 3 | 2 | 2 | 7 |
Mean score (case-control studies) | 7.8 | |||
Jordan, 2002 [10] | 3 | 2 | 2 | 7 |
Sonka, 2007 [16] | 3 | 2 | 2 | 7 |
da Silva, 2008 [17] | 3 | 2 | 2 | 7 |
Mean score (cross-sectional studies) | 7 | |||