Table 2.
Risk of bias of included studies.
| Reference | Tomoyuki (20) | Lundblad (21) | Danqing (12) | Sarah (22) | Elisabetta (23) | Yi-xian (24) | Danqing (25) | Jones et al. (26) | Shin-ichi (27) |
|---|---|---|---|---|---|---|---|---|---|
| A | Y | Y | Y | Y | Y | Y | Y | Y | Y |
| B | Y | Y | Y | N | Y | Y | N | Y | Y |
| C | N | Y | Y | Y | Y | N | Y | Y | Y |
| D | N | N | Y | N | N | N | N | N | N |
| E | Y | Y | Y | Y | Y | Y | Y | Y | Y |
| F | Y | Y | Y | N | Y | Y | Y | Y | Y |
| Total | 4 | 5 | 6 | 3 | 5 | 4 | 4 | 5 | 5 |
Studies fulfilling the criteria of: A: peer-reviewed publication; B: random allocation to group; C: blinded assessment of outcome; D: a sample size calculation; E: compliance with animal welfare regulations; and F: a statement of a potential conflict of interest. Y, yes; N, no.