| 1. Was a priori design provided? | □ Yes □ No □ Can't answer □ Not applicable |
| 2. Was there duplicate study selection and data extraction? | □ Yes □ No □ Can't answer □ Not applicable |
| 3. Was a comprehensive literature search performed? | □ Yes □ No □ Can't answer □ Not applicable |
| 4. Was the status of publication (i.e. grey literature) used as an inclusion criterion? | □ Yes □ No □ Can't answer □ Not applicable |
| 5. Was a list of studies (included and excluded) provided? | □ Yes □ No □ Can't answer □ Not applicable |
| 6. Were the characteristics of the included studies provided? | □ Yes □ No □ Can't answer □ Not applicable |
| 7. Was the scientific quality of the included studies assessed and documented? | □ Yes □ No □ Can't answer □ Not applicable |
| 8. Was the scientific quality of the included studies used appropriately in formulating conclusions? | □ Yes □ No □ Can't answer □ Not applicable |
| 9. Were the methods used to combine the findings of studies appropriate? | □ Yes □ No □ Can't answer □ Not applicable |
| 10. Was the likelihood of publication bias assessed? | □ Yes □ No □ Can't answer □ Not applicable |
| 11. Was the conflict of interest included? | □ Yes □ No □ Can't answer □ Not applicable |
Adapted from: Shea BJ, et al. BMC Medical Research Methodology. 2007
From: Appendix C, Risk of Bias Assessment Forms and Summaries
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