Table 1.
Methodological quality
| AMSTAR Checklist | modified AMSTAR Checklist | “YES” N (%) | “NO” N (%) | “Cannot answer” N (%) |
|---|---|---|---|---|
| 1. Was an ‘a priori’ design provided? | 6 (9.5) | 0 | 57 (90.5) | |
| 2. Was there duplicate study selection and data extraction? | 2.1 Were there at least two independent data extractors for study selection? | 45 (71.4) | 4 (6.3) | 14 (22.2) |
| 2.2 Was there a consensus procedure for disagreements in study selection? | 38 (60.3) | 5 (7.9) | 20 (31.7) | |
| 2.3 Were there at least two independent data extractors for data extraction? | 46 (73.0) | 3 (4.8) | 14 (22.2) | |
| 2.4 Was there a consensus procedure for disagreements in data extraction? | 39 (61.9) | 5 (7.9) | 20 (31.7) | |
| 3. Was a comprehensive literature search performed? | 3.1 Were there at least 2 electronic sources searched? | 62 (98.4) | 1 (1.6) | 0 |
| 3.2 Did the report include search years? | 61 (96.8) | 1 (1.6) | 1 (1.6) | |
| 3.3 Were key words and/or MESH terms stated and where feasible the search strategy provided? | 61 (96.8) | 2 (3.2) | 0 | |
| 3.4 Were there supplementary searches? | 49 (77.8) | 9 (14.2) | 5 (7.9) | |
| 4. Was the status of publication (i.e., gray literature) used as an inclusion criterion? | 4.1 Were there any restrictions for publication type? | 8 (13.0) | 36 (57.1) | 19 (29.7) |
| 4.2 Were there any restrictions for language? | 22 (34.4) | 25 (39.1) | 17 (30.2) | |
| 5. Was a list of studies provided? | 5.1 Was a list of included studies provided? | 63 (100) | 0 | 0 |
| 5.2 Was a list of excluded studies provided? | 4 (6.3) | 59 (93.7) | 0 | |
| 6. Were the characteristics of the included studies provided? | 6.1 Were the demographics of the participants provided? | 52 (82.5) | 11 (17.4) | 0 |
| 6.2 Were the characteristics of the interventions provided? | 59 (93.7) | 4 (6.4) | 0 | |
| 6.3 Were the characteristics of the outcomes provided? | 40 (63.5) | 23 (36.5) | 0 | |
| 7. Was the scientific quality of the included studies assessed and documented? | 7.1 Were there ‘a priori’ methods of assessment being provided? | 55 (87.3) | 8 (12.7) | 0 |
| 7.2 Was a “risk of bias” table shown in a graphic form? | 55 (87.3) | 8 (12.7) | 0 | |
| 8. Was the scientific quality of the included studies used appropriately in formulating conclusions? | 8.1 Were the results of the methodological rigor and scientific quality considered in the analysis of the review? | 35 (55.6) | 26 (41.7) | 2 (3.2) |
| 8.2 Were the results of the methodological rigor and scientific quality considered in the conclusions of the review? | 37 (58.7) | 22 (34.9) | 4 (6.3) | |
| 9. Were the methods used to combine the findings of studies appropriate? | 9.1 Was the homogeneity test (i.e., Chi-squared test for homogeneity, I2) conducted when pooling results? | 61 (96.8) | 2 (3.2) | 0 |
| 9.2 Was a random effects model used and/or the clinical appropriateness of combing taken into consideration when heterogeneity exists? | 61 (96.8) | 2 (3.2) | 0 | |
| 10. Was the likelihood of publication bias assessed? | 20 (31.7) | 42 (66.7) | 1 (1.6) | |
| 11. Was the conflict of interest stated? | 11.1 Were the sources of support for the SR reported? | 47 (74.6) | 16 (25.4) | 0 |
| 11.2 Were the sources of support for the included primary studies reported? | 1 (1.6) | 62 (98.4) | 0 |