Table 3. Assessment of the methodological quality of the studies included in this systematic review.
| Criteria evaluated* | Reference score | Frohlich et al. (2014) 22 | Zenteno et al. (2009) 23 | Mattiello et al. (2008) 11 | Gerbase et al. (2008) 24 |
|---|---|---|---|---|---|
| Study question | 2 | 2 | 2 | 2 | 2 |
| Study population | 8 | 5 | 5 | 8 | 5 |
| Comparability of individuals for observational studies | 22 | 19 | 19 | 19 | 17 |
| Exposure or intervention | 11 | 11 | 11 | 11 | 11 |
| Result measurements | 20 | 15 | 15 | 15 | 15 |
| Statistical analysis | 19 | 12 | 12 | 14 | 12 |
| Results | 8 | 8 | 8 | 8 | 8 |
| Discussion | 5 | 5 | 5 | 5 | 3 |
| Funding and sponsorship | 5 | 0 | 0 | 0 | 0 |
| Total score | 100 | 77 | 77 | 82 | 73 |
*Some items assessed in this scale did not directly apply to the design of the studies.