Table 1 Quality assessment using AMSTAR guidelines
AMSTAR quality grouping (range) | Number | Percent | |
|---|---|---|---|
Low (0–4) | 74 | 83.1 | |
Medium (5–8) | 14 | 15.7 | |
High (9–11) | 1 | 1.1 | |
Item analyses | % yes | ||
1. | Was an “a priori” design provided? | 13.5 | |
2. | Was there duplicate study selection and data extraction? | 21.4 | |
3. | Was a comprehensive literature search performed? | 20.2 | |
4. | Was the status of publication (i.e., grey literature) used as an inclusion criterion? | 19.1 | |
5. | Was a list of studies (included and excluded) provided? | 3.4 | |
6. | Were the characteristics of the included studies provided? | 95.5 | |
7. | Was the scientific quality of the included studies assessed and documented? | 31.5 | |
8. | Was the scientific quality of the included studies used appropriately in formulating conclusions? | 21.4 | |
9. | Were the methods used to combine the findings of studies appropriate? | 52.8 | |
10. | Was the likelihood of publication bias assessed? | 15.7 | |
11. | Were potential conflicts of interest included? | 0.0 | |