Table 3 Newcastle‒Ottawa Scale risk of bias assessment scores for case‒control studies
Study | Selection | Comparability | Exposure | Overall quality | |||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
Adequate case definition with independent validation | Cases representative | Selection of community control participants | Controls have no history of disease outcome | Comparable on confounders | Determination of exposure factors | The same method of ascertaining cases and controls | Nonresponse rate same for both groups | ||||
study control for the most important factors | study control for the other important factors | Independent blind assessment | Record linkage | ||||||||
Breda, 2013 [19] | 1 | 1 | 0 | 1 | 1 | 0 | 0 | 1 | 1 | 0 | 6 |
Bos, 2016 [23] | 1 | 1 | 1 | 1 | 1 | 0 | 0 | 1 | 1 | 0 | 7 |