Table 3 Risk of bias assessment
Study | Focused issue | Recruitment | Exposure accurately measured | Outcome accurately measured | Confounding factors | Follow up | Results | Precision of results | Believability of results | Applicability | Fit with evidence | Implications | Risk of bias |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Ajalloueyan | Yes | Good | Yes | Yes | Steps taken to mitigate, limitations not formally addressed | Well documented | Well documented | Poor | Fair | Good | Unsure | Fair | B |
Jin | Yes | Poor | Yes | Yes | Few steps taken to mitigate, limitations weakly addressed | Poorly described | Well documented | Fair | Fair | Good | Unsure | Unsure | C |
De Kegel | Yes | Good | Yes | Yes | Steps taken to mitigate, limitations formally addressed | Well documented | Well documented | Fair | Good | Good | Unsure | Fair | A |
Licameli | Yes | Good | Yes | Yes | Some steps taken to mitigate, limitations formally addressed | Well documented | Well documented | Fair | Good | Good | Good | Fair | A |
Devroede | Yes | Fair | Yes | Yes | Steps taken to mitigate, limitations formally addressed | Well documented | Well documented | Fair | Fair | Good | Unsure | Fair | B |
Psillas | Yes | Fair | Yes | Yes | Few steps taken to mitigate, limitations somewhat addressed | Well documented | Well documented | Fair | Fair | Good | Good | Unsure | B |
Xu | Yes | Good | Yes | Yes | Some steps taken to mitigate, limitations somewhat addressed | Well documented | Well documented | Fair | Good | Good | Good | Fair | A |
Thierry | Yes | Good | Yes | Yes | Steps taken to mitigate, limitations somewhat addressed | Well documented | Well documented | Fair | Good | Good | Good | Fair | A |
Bogle | Yes | Poorly described | Yes | Poorly described | Not mitigated, limitations formally addressed | Poorly described | Poorly described, small sample size | Poor | Poorly described | Poor | Unsure | Poor | C |
Gupta | Yes | Good | Yes | Yes | Some steps taken to mitigate, limitations not formally addressed | Well documented | Well documented | Fair | Fair | Good | Good | Fair | B |
Hazzaa | Yes | Good | Yes | Yes | Some steps taken to mitigate, limitations not formally addressed | Well documented | Well described | Good | Good | Good | Good | Fair | A |