Table 3

Results of Downs and Black Checklist Application in the included studies

Study criteria40 and 41 (combined)4243444546474849
1111111111
2111111111
3111111111
4111111111
5 (/2)212222211
6111111111
7111111110
8000000000
9111111111
10011010110
11UTD/01000UTD/0000
121UTD/0UTDUTD/0000UTD/0UTD/0
13UTD/0UTD/00UTD/00UTD/0UTD/01UTD/0
14000000000
15UTD/0UTD/0UTD/0UTD/00UTD/0UTD/011
16111111111
1710UTD/0UTD/0UTD/01111
18111111111
19111111111
20111111111
2111UTD/01UTD/00011
2201UTD/0UTD/0UTD/01UTD/01UTD/0
23 removedXXXXXXXXX
24 rmovedXXXXXXXXX
251UTD/01UTD/0UTD/01110
2600UTD/0UTD/0UTD/0UTD/0UTD/0UTD/0UTD/0
27(/1)100000000
Total/26181615141416161914
Scores in percentage696258545462627354
  • 1. Is the hypothesis/aim/objective of the study clearly described?

  • 2. Are the main outcomes to be measured clearly described in the Introduction or Methods section?

  • 3. Are the characteristics of the patients included in the study clearly described?

  • 4. Are the interventions of interest clearly described?

  • 5. Are the distributions of principal confounders in each group of subjects to be compared clearly described?

  • 6. Are the main findings of the study clearly described?

  • 7. Does the study provide estimates of the random variability in the data for the main outcomes?

  • 8. Have all important adverse events that may be a consequence of the intervention been reported?

  • 9. Have the characteristics of patients lost to follow-up been described?

  • 10. Have the actual probability values been reported (eg, 0.035 rather than <0.05) for the main outcomes except where the probability value is less than 0.001?

  • 11. Were the subjects asked to participate in the study representative of the entire population from which they were recruited?

  • 12. Were those subjects who were prepared to participate representative of the entire population from which they were recruited?

  • 13. Were the staff, places and facilities where the patients were treated representative of the treatment the majority of patients receive?

  • 14. Was an attempt made to blind study participants to the intervention they have received?

  • 15. Was an attempt made to blind those measuring the main outcomes of the intervention?

  • 16. If any of the results of the study were based on ‘data dredging’, was this made clear?

  • 17. In trials and cohort studies, do the analyses adjust for different lengths of follow-up of patients, or in case–control studies, is the time period between the intervention and outcome the same for cases and controls?

  • 18. Were the statistical tests used to assess the main outcomes appropriate?

  • 19. Was compliance with the intervention/s reliable?

  • 20. Were the main outcome measures used accurate (valid and reliable)?

  • 21. Were the patients in different intervention groups (trials and cohort studies) or were the cases and controls (case–control studies) recruited from the same population?

  • 22. Were the study participants in different intervention groups (trials and cohort studies) or were the cases and controls (case–control studies) recruited over the same period of time?

  • 25. Was there adequate adjustment for confounding in the analyses from which the main findings were drawn?

  • 26. Were losses of patients to follow-up taken into account?

  • 27. Was there evidence of a power calculation?