Table 3 Evaluation of trial quality
Quality Index items | Imamura et al. (1998) | Tillu and Gupta (1998) | Perez Millan and Foster (2001) |
|---|---|---|---|
Reporting | Â | Â | Â |
1. Study hypothesis/aim/objective | 1 | 1 | 1 |
2. Main outcomes | 1 | 1 | 1 |
3. Characteristics of the participants | 0 | 0 | 0 |
4. Interventions of interest | 0 | 1 | 0 |
5. Distributions of principal confounders in each group | 0 | 0 | 0 |
6. Main findings | 0 | 1 | 1 |
7. Estimates of random variability for main outcomes | 1 | 0 | 1 |
8. All the important adverse events that may be a consequence of intervention | 0 | 0 | 0 |
9. Characteristics of patients lost to follow-up | 0 | 1 | 1 |
10. Actual probability values for main outcomes | 0 | 1 | 0 |
External validity | Â | Â | Â |
11. Were subjects who were asked to participate representative of the entire population from which they were recruited? | 1 | 1 | 0 |
12. Were subjects who were prepared to participate representative of the entire population from which they were recruited? | 0 | 0 | 0 |
13. Were the staff, places, and facilities representative of the treatment the majority of subjects received? | 1 | 0 | 1 |
Internal validity (bias) | Â | Â | Â |
14. Was an attempt made to blind subjects to the intervention they received? | 0 | 0 | 0 |
15. Was an attempt made to blind those measuring main outcomes of the intervention? | 0 | 0 | 0 |
16. If any of the results of the study were based on"data dredging", was this made clear? | 0 | 1 | 1 |
17. Do analyses adjust for different lengths of follow-up? | 0 | 1 | 1 |
18. Were appropriate statistical tests used to assess the main outcomes? | 1 | 1 | 1 |
19. Was compliance with the intervention reliable? | 1 | 1 | 1 |
20. Were main outcome measures reliable and valid? | 0 | 0 | 0 |
Internal validity (selection bias) | Â | Â | Â |
21. Were patients in different intervention groups recruited from the same population? | 0 | 0 | 0 |
22. Were subjects in different intervention groups recruited over the same period of time? | 0 | 0 | 0 |
23. Were subjects randomized to intervention groups? | 0 | 0 | 0 |
24. Was the randomized intervention assignment concealed from both patients and staff until recruitment was complete and irrevocable? | 0 | 0 | 0 |
* 25. Was there adequate adjustment for confounding in the analyses from which main findings were drawn? | x | x | x |
26. Were losses of subjects to follow-up taken into account? | 0 | 1 | 1 |
Power | Â | Â | Â |
* 27. Did the study have sufficient power to detect a clinically important effect where the probability for a difference due to chance was less than 5%? | x | x | x |
Total score (/27) | 7 | 12 | 11 |