Table 3.
Quality ratings for the studies included on the basis of Newcastle–Ottawa quality assessment scale (n = 14).
| First Author, Publication Year | Selection | Comparability | Outcome | Total Score |
|---|---|---|---|---|
| Kerosuo, 1997 [5] | 4 | 1 | 3 | 8 |
| Ağaoğlu, 2001 [13] | 4 | 2 | 3 | 9 |
| Matos de Souza, 2008 [11] | 3 | 1 | 3 | 7 |
| Singh, 2008 [22] | 3 | 1 | 3 | 7 |
| Petoumenou, 2009 [4] | 4 | 2 | 3 | 9 |
| Sahoo, 2011 [10] | 3 | 2 | 3 | 8 |
| Ousehal, 201 [6] | 3 | 2 | 3 | 8 |
| Nayak, 2015 [2] | 3 | 0 | 3 | 6 |
| Kumar, 2016 [23] | 3 | 2 | 3 | 8 |
| Mean score (cross-sectional studies) | 7.78 | |||
| Amini, 2012 [24] | 2 | 2 | 3 | 7 |
| Yassaei, 2013 [25] | 2 | 2 | 3 | 7 |
| Gölz, 2016 [1] | 2 | 2 | 2 | 6 |
| Mean score (cohort studies) | 6.67 | |||
| Amini, 2012 [26] | 4 | 2 | 2 | 8 |
| Talic, 2013 [15] | 3 | 2 | 2 | 7 |
| Mean score (case-control studies) | 7.50 | |||