Table 3.
Risk of bias index
| Article | Reportinga | External Validityb | Internal Validityb | |||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1. Study hypothesis/aim/objective clearly described? | 2. Main outcome measures clearly described? | 3. Characteristics of included patients clearly described? | 4. Principal assessment parameters clearly described? | 5. Distributions of principal confounders per group clearly described? | 6. Main study findings clearly described? | 7. Provides estimates of random variability for main outcomes? | 10. Actual probability values reported? | 11. Subjects asked to participate represent entire recruited population? | 12. Subjects prepared to participate represent entire recruited population? | 15. Attempt made to blind those measuring main outcomes? | 16. Any results based on data dredging made clear? | 18. Statistical tests were appropriate? | 20. Main outcome measures accurate? | 21. Cases / controls recruited from same population? | 22. Cases / controls recruited over same time period? | 25. Adequate adjustment for confounding? | Total score (19) | |
| Kalichman [31]c | Y (1) | Y (1) | Y (1) | Y (2) | P (1) | Y (1) | Y (1) | Y (1) | Y (1) | Y (1) | Y (1) | Y (1) | Y (1) | Y (1) | Y (1) | Y (1) | Y (1) | 18 |
| Kalichman [32]c | Y (1) | Y (1) | Y (1) | Y (2) | P (1) | Y (1) | Y (1) | Y (1) | Y (1) | Y (1) | Y (1) | Y (1) | Y (1) | Y (1) | Y (1) | Y (1) | Y (1) | 18 |
| Kim [16] | Y (1) | Y (1) | Y (1) | Y (2) | Y (2) | Y (1) | Y (1) | Y (1) | Y (1) | U (0) | Y (1) | Y (1) | Y (1) | Y (1) | Y (1) | Y (1) | Y (1) | 18 |
| Battie [15] | Y (1) | Y (1) | Y (1) | Y (2) | Y (2) | Y (1) | Y (1) | Y (1) | U (0) | U (0) | Y (1) | Y (1) | Y (1) | Y (1) | Y (1) | Y (1) | Y (1) | 17 |
| Farshad [18] | Y (1) | Y (1) | Y (1) | Y (2) | Y (2) | Y (1) | Y (1) | Y (1) | U (0) | U (0) | Y (1) | Y (1) | Y (1) | Y (1) | Y (1) | Y (1) | Y (1) | 17 |
| Fortin [41] | Y (1) | Y (1) | Y (1) | Y (2) | Y (2) | Y (1) | Y (1) | Y (1) | U (0) | U (0) | Y (1) | Y (1) | Y (1) | Y (1) | Y (1) | Y (1) | Y (1) | 17 |
| Altinkaya [35] | Y (1) | Y (1) | Y (1) | Y (2) | Y (2) | Y (1) | N (0) | Y (1) | U (0) | U (0) | Y (1) | Y (1) | Y (1) | Y (1) | Y (1) | Y (1) | Y (1) | 16 |
| Jiang [53] | Y (1) | Y (1) | Y (1) | Y (2) | Y (2) | Y (1) | Y (1) | Y (1) | U (0) | U (0) | U (0) | Y (1) | Y (1) | Y (1) | Y (1) | Y (1) | Y (1) | 16 |
| Kalichman [49] | Y (1) | Y (1) | Y (1) | Y (2) | N (0) | Y (1) | Y (1) | Y (1) | Y (1) | U (0) | Y (1) | Y (1) | Y (1) | Y (1) | Y (1) | Y (1) | Y (1) | 16 |
| Abbas [52] | Y (1) | Y (1) | Y (1) | Y (2) | Y (2) | Y (1) | Y (1) | Y (1) | U (0) | U (0) | U (0) | Y (1) | Y (1) | Y (1) | Y (1) | N (0) | Y (1) | 15 |
| Boyaci [36] | Y (1) | Y (1) | Y (1) | Y (2) | P (1) | Y (1) | Y (1) | Y (1) | U (0) | U (0) | N (0) | Y (1) | Y (1) | Y (1) | Y (1) | Y (1) | Y (1) | 15 |
| Zhao [47] | Y (1) | Y (1) | Y (1) | Y (2) | Y (2) | Y (1) | Y (1) | N (0) | U (0) | U (0) | U (0) | Y (1) | Y (1) | Y (1) | Y (1) | Y (1) | Y (1) | 15 |
| Bhadresha [40] | Y (1) | Y (1) | Y (1) | Y (2) | P (1) | Y (1) | Y (1) | Y (1) | U (0) | U (0) | U (0) | Y (1) | Y (1) | Y (1) | Y (1) | Y (1) | N (0) | 14 |
| Mattila [46] | N (0) | Y (1) | Y (1) | Y (2) | P (1) | Y (1) | Y (1) | N (0) | Y (1) | Y (1) | U (0) | Y (1) | Y (1) | Y (1) | Y (1) | U (0) | Y (1) | 14 |
| Ogon [54] | Y (1) | Y (1) | Y (1) | Y (2) | Y (2) | Y (1) | Y (1) | Y (1) | U (0) | U (0) | U (0) | Y (1) | Y (1) | Y (1) | U (0) | U (0) | Y (1) | 14 |
| Sebro [50] | Y (1) | Y (1) | Y (1) | Y (2) | Y (2) | N (0) | N (0) | Y (1) | U (0) | U (0) | U (0) | Y (1) | Y (1) | Y (1) | Y (1) | Y (1) | Y (1) | 14 |
| Yarjanian [20] | Y (1) | Y (1) | Y (1) | P (1) | P (1) | Y (1) | Y (1) | Y (1) | U (0) | U (0) | Y (1) | Y (1) | Y (1) | U (0) | Y (1) | Y (1) | Y (1) | 14 |
| Yoshihara [22] | Y (1) | Y (1) | N (0) | Y (2) | Y (2) | Y (1) | Y (1) | N (0) | U (0) | U (0) | U (0) | Y (1) | Y (1) | Y (1) | Y (1) | Y (1) | Y (1) | 14 |
| Yu [51] | Y (1) | Y (1) | Y (1) | P (1) | P (1) | Y (1) | Y (1) | Y (1) | U (0) | U (0) | Y (1) | Y (1) | U (0) | Y (1) | Y (1) | Y (1) | Y (1) | 14 |
| Hyun [38] | Y (1) | Y (1) | Y (1) | Y (2) | P (1) | Y (1) | Y (1) | N (0) | U (0) | U (0) | Y (1) | Y (1) | Y (1) | Y (1) | Y (1) | U (0) | N (0) | 13 |
| Yoshihara [33] | Y (1) | Y (1) | Y (1) | Y (2) | Y (2) | N (0) | N (0) | N (0) | U (0) | U (0) | U (0) | Y (1) | Y (1) | Y (1) | Y (1) | Y (1) | Y (1) | 13 |
| Ford [45] | N (0) | Y (1) | N (0) | Y (2) | P (1) | Y (1) | Y (1) | N (0) | U (0) | U (0) | U (0) | Y (1) | Y (1) | Y (1) | Y (1) | Y (1) | Y (1) | 12 |
| Frost [42] | Y (1) | Y (1) | Y (1) | Y (2) | Y (2) | N (0) | Y (1) | N (0) | U (0) | U (0) | U (0) | Y (1) | Y (1) | Y (1) | U (0) | U (0) | Y (1) | 12 |
| Dangaria [37] | Y (1) | Y (1) | Y (1) | P (1) | P (1) | Y (1) | N (0) | N (0) | U (0) | U (0) | U (0) | Y (1) | Y (1) | Y (1) | Y (1) | U (0) | Y (1) | 11 |
| Kong [39] | Y (1) | Y (1) | Y (1) | P (1) | Y (2) | Y (1) | Y (1) | N (0) | U (0) | U (0) | U (0) | Y (1) | Y (1) | U (0) | U (0) | U (0) | Y (1) | 11 |
| Bajek [44] | Y (1) | Y (1) | N (0) | Y (2) | P (1) | Y (1) | Y (1) | N (0) | U (0) | U (0) | U (0) | Y (1) | Y (1) | Y (1) | U (0) | U (0) | N (0) | 10 |
| Sun [43] | Y (1) | N (0) | Y (1) | P (1) | P (1) | Y (1) | N (0) | N (0) | U (0) | U (0) | U (0) | Y (1) | Y (1) | Y (1) | Y (1) | Y (1) | U (0) | 10 |
| Jowett [48] | Y (1) | Y (1) | N (0) | Y (2) | P (1) | N (0) | N (0) | N (0) | U (0) | U (0) | U (0) | Y (1) | U (0) | Y (1) | U (0) | U (0) | N (0) | 7 |
| Total “Yes” (28) | 26 | 27 | 24 | 23 | 14 | 24 | 22 | 16 | 5 | 3 | 11 | 28 | 26 | 26 | 23 | 19 | 23 | |
aFor items 4 & 5, articles that provided some but not all relevant criteria were rated as “partial”. For item 10, articles were rated “yes” if actual values were provided for the majority of reported outcomes
bFor items 11-25, articles were rated as “unable to be determined” if insufficient details were provided to make a determination. For item 15, articles were rated as “unable to be determined” if it was unclear regarding blinding when the same investigators were involved in obtaining the pathology details and performing the muscle evaluations; this was also the case when it was unclear if the clinical pathology and muscle assessments were performed by the same investigators
cThese studies appeared to use different methodologies to analyse the same dataset so were combined for final analysis