Study | Year | Study design | Ethnicity | Country | Sample size | Age (years) | Included varicocele patients | Quality score | |
---|---|---|---|---|---|---|---|---|---|
Varicocele | Non-varicocele | ||||||||
Handel et al. [16] | 2006 | Case-control | Caucasian | USA | 1093 | 2120 | NA | Left. right and bilateral | 8 |
Kilic et al. [13] | 2007 | Case-control | Caucasian | Turkey | 52 | 100 | 14–50 | Left. right and bilateral | 7 |
Tsao et al. [19] | 2009 | Cross-sectional | Asian | China | 490 | 560 | 18–27 | Left. right and bilateral | 8 |
Chen et al. [18] | 2010 | Case-control | Asian | China | 102 | 95 | 18–50 | NA | 7 |
Farhan et al. [27] | 2010 | Case-control | Asian | Iraq | 206 | 206 | NA | Left. right and bilateral | 7 |
Chancwalters et al. [28] | 2012 | Case-control | Caucasian | USA | 330 | 749 | 18–40 | Left. right and bilateral | 7 |
Soylemez et al. [21] | 2012 | Cross-sectional | Caucasian | Turkey | 498 | 1563 | 19–34 | Left. right and bilateral | 7 |
Yigitler et al. [29] | 2012 | Cross-sectional | Caucasian | Turkey | 750 | 11,831 | 16–23 | NA | 9 |
Özçelik et al. [30] | 2013 | Case-control | Caucasian | Turkey | 75 | 100 | 20–30 | NA | 7 |
Rais et al. [31] | 2013 | Cross-sectional | Caucasian | Israel | 47,398 | 1,275,663 | 17–18 | NA | 9 |
Gokce et al. [8] | 2013 | Cross-sectional | Caucasian | Turkey | 587 | 1255 | 18–50 | Right and bilateral | 8 |
Doğantekin et al. [32] | 2014 | Cross-sectional | Caucasian | T urkey | 210 | 390 | 21–38 | Left. right and bilateral | 7 |
Bae et al. [33] | 2014 | Case-control | Asian | Korea | 211 | 102 | NA | NA | 7 |
Gorur et al. [34] | 2015 | Case-control | Caucasian | Turkey | 138 | 117 | 18–45 | NA | 7 |
Liu et al. [35] | 2015 | Case-control | Asian | China | 73 | 104 | 18–50 | NA | 7 |
Shafi et al. [36] | 2015 | Case-control | Asian | Iran | 153 | 250 | 18–40 | Left. right and bilateral | 7 |
Liu et al. [7] | 2017 | Cross-sectional | Asian | China | 1911 | 37,648 | 21–49 | Left. right and bilateral | 8 |
Pallotti et al. [3] | 2018 | Case-control | Caucasian | Italy | 2085 | 2080 | NA | Left. right and bilateral | 7 |