Table A1.
Quality assessment results (modified Downs and Black checklist 11). The Ichiki 2017 study was not separately analyzed as the data came from the Tei 2016 study. Questions: green=1 point, red=0 points. Total points: scale: red‐yellow‐green (0 points red, 32 point green)
| Question (modified Downs and Black method) | Kihara 2002 | Kihara 2004 | Miyata 2008 | Kihara 2009 | Kuwahata 2011 | Fujita 2011 | Tei 2016 | Ichiki 2017 (= Tei 2016) |
|---|---|---|---|---|---|---|---|---|
| Reporting | ||||||||
| 1. Is the hypothesis/aim/objective of the study clearly described? | 1 | 1 | 1 | 1 | 1 | 1 | 1 | |
| 2. Are the main outcomes to be measured clearly described in the Introduction or Methods section? | 1 | 1 | 1 | 1 | 1 | 1 | 1 | |
| 3. Are the characteristics of the patients included in the study clearly described? | 0 | 1 | 1 | 1 | 1 | 1 | 1 | |
| 4. Are the interventions of interest clearly described? | 1 | 1 | 1 | 1 | 1 | 1 | 1 | |
| 5. Are the distributions of principal confounders in each group of subjects to be compared clearly described? (0‐2) | 1 | 2 | 2 | 2 | 2 | 2 | 2 | |
| 6. Are the main findings of the study clearly described? | 1 | 1 | 1 | 1 | 1 | 1 | 1 | |
| 7. Does the study provide estimates of the random variability in the data for the main outcomes? | 1 | 1 | 1 | 1 | 1 | 1 | 1 | |
| 8. Have all important adverse events that may be a consequence of the intervention been reported? | 1 | 1 | 1 | 0 | 0 | 0 | 1 | |
| 9. Have the characteristics of patients lost to follow‐up been described? | 1 | 1 | 1 | 1 | 1 | 1 | 1 | |
| 10. Have 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? | 1 | 0 | 0 | 0 | 0 | 0 | 1 | |
| External validity | ||||||||
| 11. Were the subjects asked to participate in the study representative of the entire population from which they were recruited? | 0 | 0 | 0 | 0 | 0 | 0 | 0 | |
| 12. Were those subjects who were prepared to participate representative of the entire population from which they were recruited? | 0 | 0 | 0 | 0 | 0 | 0 | 0 | |
| 13. Were the staff, places, and facilities where the patients were treated, representative of the treatment the majority of patients receive? | 1 | 1 | 1 | 1 | 1 | 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 | 0 | 0 | |
| 15. Was an attempt made to blind those measuring the main outcomes of the intervention? | 0 | 0 | 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 | 1 | 1 | 1 | 1 | |
| 17. In trials and cohort studies, do the analyses adjust for different lengths of follow‐up of patients? | 1 | 1 | 1 | 1 | 1 | 1 | 1 | |
| 18. Were the statistical tests used to assess the main outcomes appropriate? | 1 | 1 | 1 | 1 | 1 | 1 | 1 | |
| 19. Was compliance with the intervention/s reliable? | 1 | 1 | 1 | 1 | 1 | 1 | 1 | |
| 20. Were the main outcome measures used accurate (valid and reliable)? | 1 | 1 | 1 | 1 | 1 | 1 | 1 | |
| Internal validity—confounding (selection bias) | ||||||||
| 21. Were the patients in different intervention groups (trials and cohort studies) recruited from the same population? | 0 | 0 | 1 | 1 | 1 | 1 | 1 | |
| 22. Were study subjects in different intervention groups (trials and cohort studies) recruited over the same period of time? | 0 | 0 | 0 | 1 | 0 | 1 | 1 | |
| 23. Were study subjects randomized to intervention groups? | 0 | 1 | 1 | 0 | 1 | 1 | 1 | |
| 24. Was the randomized intervention assignment concealed from both patients and healthcare staff until recruitment was complete and irrevocable? | 0 | 0 | 0 | 0 | 0 | 0 | 0 | |
| 25. Was there adequate adjustment for confounding in the analyses from which the main findings were drawn? | 0 | 1 | 1 | 1 | 1 | 0 | 1 | |
| 26. Were losses of patients to follow‐up taken into account? | 1 | 1 | 1 | 1 | 1 | 1 | 0 | |
| Power | ||||||||
| 27. Did the study present a power calculation of significance? (modified) (0‐5) | 0 | 0 | 0 | 0 | 0 | 0 | 0 | |
| Total: (of 32) | 16 | 19 | 20 | 19 | 19 | 19 | 21 | 21 |
No = 0, yes = 1, unable to determine = 0.