Table 4 Quality appraisal for observational studies according to the Critical Appraisal Skills Programme (CASP)
Source | Type of study | 1. Focused issue | 2. Appropriate method | 3. Recruitment | 4. Selection of controls | 5. Exposure measured | 6. Outcome measured | 7. Confounding factors identified | 8. Confounding design/analysis | 9. Follow up complete | 10. Follow up long | 11. Results of this study | 12. How precise results/risk estimate | 13. Believe results | 14. Results be applied | 15. Results fit evidence |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Evans 2010 [32] | Population-based cohort study | Y | Y | Y | NA | Y | Y | N | N | Y | U | Â | Â | Y | Y | U |
Hung 2013 [33] | population-based retrospective cohort study | Y | U | Y | NA | Y | N | N | Y | U | U | Â | Â | Y | Y | Y |
Inzucchi 2005 [34] | Retrospective cohort study | Y | Y | Y | NA | N | Y | Y | Y | Y | N | Â | Â | U | Y | U |
Lapane 2015 [37] | Retrospective cohort study | Y | Y | Y | NA | Y | N | Y | Y | U | N | Â | Â | Y | Y | Y |
MacDonald 2010 [38] | Case-control study | Y | Y | Y | Y | Y | Y | Y | Y | Y | Y | Â | Â | Y | Y | Y |
Masoudi 2005 [39] | Retrospective cohort | Y | Y | Y | NA | Y | N | Y | Y | U | U | Â | Â | U | Y | U |
Moore 2013 [40] | Cross sectional study | Y | Y | N | N | N | Y | U | Y | NA | NA | Â | Â | U | U | N |
Roumie 2012 [41] | Retrospective cohort study | Y | Y | U | NA | U | U | Y | Y | U | U | Â | Â | U | Y | U |
Roussel 2010 [42] | Prospective, observational registry | Y | Y | N | NA | U | Y | U | Y | Y | U | Â | Â | Y | Y | Y |
Solomon 2009 [44] | Retrospective cohort | Y | Y | Y | NA | Y | Y | Y | Y | Y | N | Â | Â | U | Y | Y |
Tzoulaki 2009 [45] | Retrospective cohort study | Y | Y | Y | NA | U | Y | Y | Y | Y | Y | Â | Â | U | Y | Y |