Methodological quality assessment of the included studies
| 1. Clear objective | 2. Clear description of main outcomes | 3. Clear description of participant characteristics | 4. Clear description of intervention | 6. Clear description of main findings | 7. Estimates of random variability described | 11. Participants asked representative of entire population | 12. Included participants representative of entire population | 16, Planned analysis | 18. Statistical analysis appropriate | 20. Accuracy of outcome measures | 25. Adjustment for confounding | Quality index score (out of 12) | Quality index % | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Azevedo et al 200910 | 1 | 1 | 1 | 1 | 1 | 1 | 0 | 0 | 1 | 1 | 1 | 0 | 9 | 75 |
| Baur et al 200419 | 1 | 1 | 0 | 1 | 1 | 0 | 0 | 0 | 1 | 1 | 1 | 0 | 7 | 58 |
| Bennel et al 200425 | 1 | 1 | 1 | 1 | 1 | 1 | 0 | 0 | 1 | 1 | 1 | 1 | 10 | 83 |
| Bischof et al 201026 | 1 | 1 | 1 | 1 | 1 | 1 | 0 | 0 | 1 | 1 | 1 | 0 | 9 | 75 |
| Bredeweg et al 201322 | 1 | 1 | 0 | 1 | 1 | 1 | 1 | 0 | 1 | 1 | 1 | 1 | 10 | 83 |
| Crossley et al 199927 | 1 | 1 | 1 | 1 | 1 | 1 | 0 | 0 | 1 | 1 | 1 | 1 | 10 | 83 |
| Duffey et al 200030 | 0 | 1 | 1 | 1 | 1 | 1 | 0 | 0 | 1 | 1 | 1 | 1 | 9 | 75 |
| Esculier et al 201531 | 1 | 0 | 1 | 1 | 1 | 1 | 0 | 0 | 1 | 1 | 1 | 1 | 9 | 75 |
| Gerlach et al 200521 | 1 | 1 | 1 | 1 | 1 | 1 | 0 | 0 | 1 | 1 | 1 | 0 | 9 | 75 |
| Grimston et al 199118 | 1 | 0 | 1 | 1 | 1 | 1 | 0 | 0 | 1 | 1 | 1 | 0 | 8 | 67 |
| Hreljac et al 200033 | 1 | 1 | 0 | 1 | 1 | 1 | 0 | 0 | 1 | 1 | 1 | 1 | 9 | 75 |
| McCrory et al 199923 | 1 | 1 | 0 | 1 | 1 | 1 | 0 | 0 | 1 | 1 | 1 | 1 | 9 | 75 |
| Messier et al 199132 | 1 | 1 | 0 | 1 | 1 | 1 | 0 | 0 | 1 | 1 | 1 | 0 | 8 | 67 |
| Messier et al 199511 | 1 | 1 | 1 | 1 | 1 | 1 | 0 | 0 | 1 | 1 | 1 | 0 | 9 | 75 |
| Milner et al 200628 | 1 | 1 | 0 | 1 | 1 | 1 | 0 | 0 | 1 | 1 | 1 | 1 | 9 | 75 |
| Pohl et al 200829 | 1 | 1 | 1 | 1 | 1 | 1 | 0 | 0 | 1 | 1 | 1 | 1 | 10 | 83 |
| Pohl et al 200924 | 1 | 1 | 1 | 1 | 1 | 1 | 0 | 0 | 1 | 1 | 1 | 1 | 10 | 83 |
| Zifchock et al 200620 | 1 | 1 | 1 | 1 | 1 | 1 | 0 | 0 | 1 | 1 | 1 | 1 | 10 | 83 |