AMSTAR assessment of methodological characteristics (n=607)
| Category | Yes (%) | Partially/cannot tell (%) | No (%) | p Values | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
| All n=607 | ≤2009 n=230 | 2010–2014 n=377 | All n=607 | ≤2009 n=230 | 2010–2014 n=377 | All n=607 | ≤2009 n=230 | 2010–2014 n=377 | ||
| 1. Was an ‘a priori’ design provided? | 227 (37.4) | 69 (30.0) | 158 (41.9) | 310 (51.1) | 134 (58.3) | 176 (46.7) | 70 (11.5) | 27 (11.7) | 43 (11.4) | 0.010 |
| 2. Was there duplicate study selection and data extraction? | 255 (42.0) | 65 (28.3) | 190 (50.4) | 13 (2.2) | 6 (2.6) | 7 (1.9) | 339 (55.8) | 159 (69.1) | 180 (47.7) | 0.000 |
| 3. Was a comprehensive literature search performed? | 86 (14.2) | 22 (9.6) | 64 (16.9) | 392 (64.6) | 141 (61.3) | 251 (66.6) | 129 (21.2) | 67 (29.1) | 62 (16.5) | 0.000 |
| 4. Was the status of publication (ie, grey literature) used as an inclusion criterion? | 95 (15.7) | 37 (16.1) | 58 (15.4) | 0 (0.0) | 0 (0.0) | 0 (0.0) | 512 (84.3) | 193 (83.9) | 319 (84.6) | 0.817 |
| 5. Was a list of studies (included and excluded) provided? | 63 (10.4) | 20 (8.7) | 43 (11.4) | 96 (15.8) | 50 (21.7) | 46 (12.2) | 448 (73.8) | 160 (69.6) | 288 (76.4) | 0.006 |
| 6. Were the characteristics of the included studies provided? | 460 (75.8) | 158 (68.7) | 302 (80.1) | 12 (1.9) | 6 (2.6) | 6 (1.6) | 135 (22.3) | 66 (28.7) | 69 (18.3) | 0.006 |
| 7. Was the scientific quality of the included studies assessed and documented? | 317 (52.2) | 96 (41.7) | 221 (58.6) | 0 (0.0) | 0 (0.0) | 0 (0.0) | 290 (47.8) | 134 (58.3) | 156 (41.4) | 0.000 |
| 8. Was the scientific quality of the included studies used appropriately in formulating conclusions? | 357 (58.8) | 124 (53.9) | 233 (61.8) | 23 (3.8) | 8 (3.5) | 15 (3.9) | 227 (37.4) | 98 (42.6) | 129 (34.3) | 0.117 |
| 9. Were the methods used to combine the findings of studies appropriate? | 436 (71.8) | 169 (73.5) | 267 (70.8) | 150 (24.7) | 54 (23.5) | 97 (25.7) | 21 (3.5) | 7 (3.0) | 13 (3.5) | 0.055 |
| 10. Was the likelihood of publication bias assessed? | 374 (61.6) | 110 (47.8) | 264 (70.0) | 11 (1.8) | 6 (2.6) | 5 (1.3) | 222 (36.6) | 114 (49.6) | 108 (28.7) | 0.000 |
| 11. Was the conflict of interest stated? | 27 (4.5) | 8 (3.5) | 19 (5.0) | 0 (0.0) | 0 (0.0) | 0 (0.0) | 580 (95.5) | 222 (96.5) | 358 (95.0) | 0.356 |