Table S3. NOS scoring records of the included studies.
| Authors [year] (Ref.) | Selection | Comparability | Exposure | Total score | ||
|---|---|---|---|---|---|---|
| Assessment of outcome | follow-up long enough for outcomes | Adequacy of follow-up of cohorts | ||||
| Chen et al. [2013] (18) | 4 | 1 | 1 | 1 | 1 | 8 |
| Chen et al. [2012] (13) | 4 | 1 | 1 | 1 | 1 | 8 |
| Chiou et al. [2010] (19) | 4 | 1 | 0 | 1 | 1 | 7 |
| Dong et al. [2013] (33) | 4 | 1 | 1 | 0 | 1 | 7 |
| Li et al. [2016] (14) | 4 | 1 | 1 | 0 | 1 | 7 |
| Li et al. [2012] (15) | 4 | 1 | 1 | 0 | 1 | 7 |
| Li et al. [2013] (16) | 4 | 1 | 1 | 1 | 1 | 8 |
| Ni et al. [2012] (34) | 4 | 1 | 1 | 0 | 1 | 7 |
| Qiao et al. [2012] (35) | 4 | 1 | 1 | 0 | 1 | 7 |
| Sun et al. [2012] (36) | 4 | 1 | 0 | 0 | 1 | 6 |
| Tang et al. [2015] (17) | 4 | 2 | 1 | 1 | 1 | 9 |
| Wei et al. [2011] (37) | 4 | 1 | 1 | 1 | 1 | 8 |
| Xiang et al. [2015] (38) | 4 | 1 | 1 | 0 | 1 | 7 |
| Yang et al. [2014] (39) | 4 | 1 | 1 | 0 | 1 | 7 |
| Zhang et al. [2013] (40) | 4 | 2 | 1 | 1 | 1 | 9 |
| Zhou et al. [2011] (41) | 4 | 1 | 0 | 0 | 1 | 6 |
NOS, Newcastle-Ottawa Scale.