Table 4 Quality assessment ratings for included studies
Quality component | Strong rating No (%) | Moderate rating No (%) | Weak rating No (%) |
|---|---|---|---|
Selection bias | 11/32 (34.3) | 6/32 (18.8) | 15/32 (46.9) |
Study design | 22/32 (68.8) | 7/32 (21.9) | 3/32 (9.4) |
Confounders | 21/32 (65.6) | 0/32 (0.0) | 11/32 (33.3) |
Blinding | 3/32 (9.4) | 20/32 (62.5) | 9 (28.1) |
Data collection methods | 13/32 (40.6) | 0/32 (0.0) | 19/32 (59.4) |
Withdrawal and drop out | 13/32 (40.6) | 14/32 (43.8) | 5 (15.6) |
Global rating | 3/32 (9.4) | 14/32 (43.8) | 15/32 (46.9) |