Table 2 AMSTAR Assessment according to quality items
Quality items | “Yes” (%) | “No” | “Cannot answer” | “Not applicable” | |
|---|---|---|---|---|---|
n (%) | n (%) | n (%) | n (%) | ||
1 | Was an "a prior" design provided? | 22 (100.0) | 0 | 0 | 0 |
2 | Was there duplicate study selection and data extraction? | 3 (13.6) | 17 (77.3) | 2 (9.1) | 0 |
3 | Was a comprehensive literature search performed? | 11 (50.0) | 5 (22.7) | 6 (27.3) | 0 |
4 | Was the status of publication (i.e. grey literature) used as an inclusion criterion? | 4 (18.2) | 6 (27.3) | 12 (54.5) | 0 |
5 | Was a list of studies (included and excluded) provided? | 4 (18.2) | 14 (63.6) | 4 (18.2) | 0 |
6 | Were the characteristics of the included studies provided? | 22 (100.0) | 0 | 0 | 0 |
7 | Was the scientific quality of the included studies assessed and documented? | 3 (13.6) | 17 (77.3) | 2 (9.1) | 0 |
8 | Was the scientific quality of the included studies used appropriately in formulating conclusions? | 3 (13.6) | 18 (81.8) | 1 (4.5) | 0 |
9 | Were the methods used to combine the findings of studies appropriate? | 16 (72.7) | 6 (27.3) | 0 | 0 |
10 | Was the likelihood of publication bias assessed? | 5 (22.7) | 16 (72.7) | 1 (4.5) | 0 |
11 | Was the conflict of interest stated? | 11 (50.0) | 11 (50.0) | 0 | 0 |