Table 2.
Risk of bias of the included studies.
| ID | Study | ① | ② | ③ | ④ | ⑤ | ⑥ | ⑦ | ⑧ | ⑨ | ⑩ | Score |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1 | B. Feng [38] | U | Y | U | Y | Y | U | U | Y | Y | Y | 6 |
| 2 | C. Cheng [36] | U | U | U | U | U | U | U | Y | Y | Y | 3 |
| 3 | G. Li [32] | U | U | U | Y | U | U | U | U | Y | Y | 3 |
| 4 | H. Hao [28] | Y | Y | U | U | U | U | U | Y | Y | U | 4 |
| 5 | H. Yang [45] | U | Y | U | Y | U | U | U | Y | Y | Y | 5 |
| 6 | H. Yu [49] | U | Y | U | Y | U | U | U | U | Y | Y | 4 |
| 7 | K. Chen [39] | U | Y | U | Y | U | U | U | Y | Y | Y | 5 |
| 8 | K. Hou [29] | U | Y | U | Y | U | U | U | Y | Y | Y | 5 |
| 9 | K. R. Nalamolu [27] | U | Y | U | Y | U | U | U | Y | Y | U | 4 |
| 10 | L. Xu [33] | U | U | U | Y | U | U | U | Y | Y | Y | 4 |
| 11 | M. Han [40] | U | Y | U | Y | U | U | U | U | Y | Y | 4 |
| 12 | Q. Pan [43] | U | Y | U | Y | U | U | U | U | Y | Y | 4 |
| 13 | W. Wang [44] | U | Y | U | Y | U | U | U | Y | Y | Y | 5 |
| 14 | X. Huang [26] | U | Y | U | Y | U | U | U | U | Y | Y | 4 |
| 15 | X. Li [34] | U | Y | U | U | U | U | U | Y | Y | Y | 4 |
| 16 | X. Li [42] | U | Y | U | Y | U | U | Y | U | Y | Y | 5 |
| 17 | X. Liu [35] | U | Y | U | Y | U | U | U | U | Y | Y | 4 |
| 18 | Y. AN [48] | U | Y | U | Y | U | U | U | Y | Y | Y | 5 |
| 19 | Y. Ye [46] | Y | Y | Y | Y | Y | U | Y | Y | Y | Y | 9 |
| 20 | Y. Zhao [30] | U | Y | U | Y | U | U | U | U | Y | Y | 4 |
| 21 | Y. Zhao [47] | U | Y | U | Y | U | U | U | Y | Y | Y | 5 |
| 22 | Z. Hou [41] | U | Y | U | Y | U | U | U | U | Y | Y | 4 |
| 23 | Z. Pan [31] | U | Y | U | Y | U | U | U | Y | Y | Y | 5 |
| 24 | Z. Zhang [37] | U | U | U | Y | U | U | Y | U | Y | Y | 4 |
①: Was the allocation sequence adequately generated and applied; ②: were the groups similar at baseline or were they adjusted for confounders in the analysis; ③: was the allocation adequately concealed; ④: were the animals randomly housed during the experiment; ⑤: were the caregivers and/or investigators blinded from knowledge which intervention each animal received during the experiment; ⑥: were animals selected at random for outcome assessment; ⑦: was the outcome assessor blinded; ⑧: were incomplete outcome data adequately addressed; ⑨: are reports of the study free of selective outcome reporting; ⑩: was the study apparently free of other problems that could result in high risk of bias. Y: yes; N: no; U: uncertain.