Table 4 Methodological quality of the sampled 80 meta-epidemiological (ME) studies
Methodological items | Yes | No | ||
|---|---|---|---|---|
No. of ME studies | % (95% CI) | No. of ME studies | % (95% CI) | |
M1. Did the author state that they had published a protocol prior to the conduct of the ME study? | 23 | 29 (19 to 39) | 57 | 71 (61 to 81) |
M2. Did the author use a comprehensive literature search strategy? | 46 | 58 (46 to 69) | 34 | 42 (31 to 54) |
M3. Did the author give a clear description of inclusion criteria and reasons for exclusion? | 74 | 92 (87 to 98) | 6 | 8 (2 to 13) |
M4. Whether selection process was reported? | 69 | 86 (78 to 94) | 11 | 14 (6 to 22) |
M5. Did the author perform selection process in duplicate? | 40 | 50 (39 to 61) | 40 | 50 (39 to 61) |
M6. Did the author perform data extraction in duplicate?a | 52 | 88 (79 to 97) | 7 | 12 (3 to 21) |
M7. Did the author provide a list of excluded studies and justify the exclusions?b | 12 | 15 (7 to 23) | 65 | 81 (72 to 90) |
M8. Did the author evaluate the heterogeneity between included meta-analyses or trials or ME studies?c | 59 | 87 (78 to 95) | 9 | 13 (5 to 22) |
M8i. Did the author perform an investigation of sources of any heterogeneity?c | 35 | 83 (72 to 95) | 7 | 17 (5 to 28) |
M9. Whether analysis was adjusted on meta-confounders for ME studies estimating a combined difference of treatment effect?c | 54 | 79 (70 to 89) | 14 | 21 (11 to 30) |
M10. Whether clustering of trials within meta- analyses was taken into account for ME studies based on a collection of meta-analyses or previous ME studies?c | 53 | 87 (78 to 96) | 8 | 13 (4 to 22) |
M11. Did the author report any potential sources of conflict of interest, including any funding they received for conducting the ME study? | 74 | 92 (86 to 98) | 6 | 8 (2 to 14) |
M12. Whether checking experimental and control arms were reported? | 40 | 51 (39 to 62) | 40 | 49 (38 to 61) |
M13. Whether the author reclassified of outcomes reported to have the same sense of interpretation? | 56 | 71 (61 to 81) | 24 | 29 (19 to 39) |
M14. Did the author give a clear definition of trial characteristics evaluated in ME studies? | 72 | 90 (83 to 97) | 8 | 10 (3 to 17) |
M15. Did the author assess the trial characteristics evaluated in duplicate? | 64 | 80 (71 to 89) | 16 | 20 (11 to 29) |
M16. Did the author assess the methodological quality of the included ME studies or meta-analyses or trials? | 26 | 33 (22 to 44) | 54 | 67 (56 to 78) |