Table 3.

Qualitative assessment/risk of bias of the studies.

The numbers 1 to 11 refer to the items of the tool

1. Defining the source of information (survey, record review)

2. Listing the inclusion and exclusion criteria for exposed and unexposed subjects or referring to previous publications

3. Indicate time period used for identifying patients

4. Indicating whether the subjects were recruited consecutively (if not population-based)

5. Indicating if evaluators of subjective components of the study were masked from the participants

6. Description of any assessments undertaken for quality assurance purposes (e.g., test/retest of primary outcome measurements)

7. Explaining any exclusions of patients from the analysis

8. Description how confounding was assessed and/or controlled

9. If applicable, explaining how missing data were handled in the analysis

10. Summarizing patient response rates and completeness of data collection

11. Clarification of the expected follow-up (if any), and the percentage of patients with incomplete data or follow-up