Table 2.
Quality assessment scores from the Quality index tool [21]
| Quality index items | Moretti [26] | Saggini [27] | Wang [28] | Wang [29] | Schaden [17] |
|---|---|---|---|---|---|
| Reporting | |||||
| 1. Study hypotheses/aim/objective | 1 | 0 | 1 | 1 | 1 |
| 2. Main outcomes | 1 | 1 | 1 | 1 | 1 |
| 3. Participant characteristics | 1 | 1 | 1 | 1 | 1 |
| 4. Interventions of interest | 1 | 0 | 1 | 1 | 1 |
| 5. Distribution of principal confounders | 1 | 1 | 0 | 1 | 1 |
| 6. Main findings | 1 | 1 | 1 | 1 | 1 |
| 7. Estimates of random variability | 1 | 0 | 1 | 0 | 1 |
| 8. Adverse events described | 0 | 1 | 0 | 1 | 1 |
| 9. Participants lost to follow up described | 1 | 0 | 1 | 1 | 1 |
| 10. Actual probability values reported | 0 | 0 | 0 | 1 | 1 |
| External validity | |||||
| 11. Were subjects asked to participate representative of population from which they were recruited? | 0 | 0 | 0 | 0 | 0 |
| 12. Were subjects prepared to participate representative of the entire population from which they were recruited? | 0 | 0 | 0 | 0 | 0 |
| 13. Were the staff, places and facilities where the patients were treated, representative of the treatment patients received? | 1 | 1 | 0 | 1 | 1 |
| Internal validity (bias) | |||||
| 14. Was an attempt made to blind study subjects to the intervention they have received? | 0 | 0 | 0 | 0 | 0 |
| 15. Was an attempt made to blind those measuring the main outcomes of the intervention? | 0 | 0 | 0 | 0 | 0 |
| 16. If any of the results of the study were based on ‘data dredging’ was this made clear? | 1 | 1 | 1 | 0 | 1 |
| 17. Does analysis adjust for lengths of follow up or is the time period between intervention and outcome the same? | 0 | 0 | 0 | 0 | 0 |
| 18. Were the statistical tests used to assess the main outcomes appropriate? | 0 | 1 | 0 | 1 | 1 |
| 19. Was compliance with the intervention reliable? | 1 | 1 | 1 | 1 | 1 |
| 20. Were the main outcome measures used accurate (valid and reliable)? | 1 | 0 | 1 | 1 | 0 |
| Internal validity (selection bias) | |||||
| 21. Were cases and controls recruited from the same population? | 0 | 0 | 1 | 1 | 0 |
| 22. Were cases and controls recruited over the same period of time? | 1 | 1 | 1 | 0 | 1 |
| 23. Were study subjects randomised to intervention groups? | 1 | 0 | 1 | 1 | 0 |
| 24. Was randomised intervention assignment concealed from participants/researchers until recruitment complete? | 0 | 0 | 0 | 0 | 0 |
| 25. Was there adequate adjustment for confounding in the analysis from which the main findings were drawn? | 0 | * | 0 | 0 | 1 |
| 26. Were losses to follow up of patients taken into account? | 1 | 0 | 1 | 1 | 1 |
| Power | |||||
| 27. Did the study have sufficient power to detect a clinically important effect? | * | * | * | * | * |
| Total score% | 55 | 38 | 52 | 59 | 63 |
Notes:
All questions were scored on the following scale: yes = 1, unable to determine = 0, no = 0.
Question 5 is an exception with scores allocated: yes = 2, partially = 1, no = 0.
*Item removed.