Table 1. Characteristics of Studies a.
| Author | Year | Country | Method | Sample size (PCOS) | Healthy control | QAS |
|---|---|---|---|---|---|---|
| Cerda, C (1) | 2007 | Chile | Cohort | 41 | 31 | 20 |
| Zheng, RH (13) | 2008 | China | Case-Control | 60 | 60 | 18 |
| Vassilatou, E (2) | 2010 | Greece | Case-Control | 57 | 60 | 19 |
| Qu, Z (22) | 2010 | China | Case-Control | 306 | 286 | 18 |
| Faisal, A (9) | 2012 | Egypt | Cohort | 53 | 32 | 19 |
| Zueff, LF (8) | 2012 | Brazil | Case-Control | 45 | 45 | 20 |
| Karoli, R (4) | 2013 | India | Cohort | 54 | 55 | 20 |
a Abbreviation: PCOS, Polycystic Ovarian Syndrome; QAS, Quality Assessment Score.