Table 1 Characteristics of included studies
Trial | Region | Cases | Trial design | Age (years) | Male (%) | Outcome variables | aOR (95% CI) | Risk of bias |
|---|---|---|---|---|---|---|---|---|
Douglas 2003 | USA | 322 | Cohort study | 73 | 53 | OC | 0.96 (0.1-8.97) | Moderate |
Chen 2007 | CHINA | 357 | Case-control study | 65.9 | 54.1 | OC | 3.17 (1.25-8.04) | Moderate |
Bugnicourt 2009 | France | 511 | Case-control study | 65.7 | 56.8 | OC | 1.89 (1.13-3.14) | Moderate |
POWER 2011 | UK | 529 | Cohort study | 59 | 61 | OC & MO | OC: 1.48 (1-2.23) MO: 2.17 (1.22–3.87) | Low |
Koton 2012 | Israel | 1049 | Cohort study | 70 | 59 | MO | Mild: 1.6 (0.6–4.3) Severe: 1.0 (0.4–3.0) | Moderate |
Lee 2014 | Korea | 1017 | Cohort study | 67.7 | 56.7 | RE & MO | Mild: RE: 1.49 (.83-2.67) MO: 0.51 (.19-1.37) Severe: RE: 2.00 (1.07-3.71) MO: 0.54 (.19-1.53) | Moderate |
Bos2014 | Europe | 2323 | Cohort study | 69.5 | 47.8 | OC | 1.39 (0.98-1.99) | Moderate |
Kao 2015 | Netherlands | 1872 | Case-control study | NA | 53.7 | OC | 1.02 (0.98, 1.07) | Low |
Quiney 2017 | USA | 99 | Case-control study | 55 | 58.6 | OC | 2.2(1.2-3.9) | Moderate |
Zhang 2019 | China | 125 | Case-control study | NA | NA | OC | 1.98 (1.45 ~ 2.69) | Low |
Magdiˇ 2020 | Slovenia | 448 | Case-control study | 76 | 47.3 | RE & MO | RE: 3.13 (1.35-7.20) MO: 1.22 (0.93-1.56) | Moderate |
Wu 2020 | China | 694 | Cohort study | 71.6 | 50.3 | RE & MO | RE: 1.23 (0.57, 2.66) MO: 3.17 (0.42-23.79) | Low |