Table 2 Methodological quality of observation studies with EBRO assessment tool of cohort studies [38]
Item | Semba et al. 2010 [45] | Sun et al. 2012 [46] | Whitson et al. 2014 [47] | Shah et al. 2015 [50] | Dalal et al. 2009 [43] | De La Maza et al. 2008 [49] | Momma et al. 2011 [44] | Tanaka et al. 2015 [48] |
|---|---|---|---|---|---|---|---|---|
1. Are the comparing groups clearly described? | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes |
2. Can risk of bias sufficiently be excluded? | Yes | Yes | Yes | Yes | Yes | Yes | Yes | No |
3. Is the exposure clearly described and is the method for assessing the exposure adequate? | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes |
4. Is outcome clearly described and is the method for assessing the outcome adequate? | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes |
5. Has exposure outcome been blinded? | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes |
6. Is there sufficient long follow-up? | Not Applicable | Yes | Yes | Not Applicable | Not Applicable | Not Applicable | Not Applicable | Not Applicable |
7. Can selective loss-to-follow-up sufficiently be excluded? | Not Applicable | Yes | Yes | Not Applicable | Not Applicable | Not Applicable | Not Applicable | Not Applicable |
8. Have important confounders or prognostic factors been identified and are they taken into account in the design or analysis? | Yes | Yes | Yes | No | Yes | No | Yes | Yes |
9. Are the study results valid and applicable? | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes |
10. Correction for potential confounders: Odds ratio (OR), Relative Risk (RR), Absolute Risk Reduction (ARR), Mean Difference (MD), Hazard Ratio (HR) | Yes | Yes | Yes | No | Yes | No | Yes | Yes |
Overall quality score | Good | Good | Good | Moderate | Good | Moderate | Good | Good |