Table 1.
Results of the quality appraisal (n = 31).
| Study | 1. Were the criteria for inclusion in the sample clearly defined? | 2. Were the study subjects and the setting described in detail? | 3. Was the exposure measured in a valid and reliable way? | 4. Were objective, standard criteria used for measurement of the condition? | 5. Were confounding factors identified? | 6. Were strategies to deal with confounding factors stated? | 7. Were the outcomes measured in a valid and reliable way? | 8. Was appropriate statistical analysis used? |
|---|---|---|---|---|---|---|---|---|
| Chen, J. E., 201848 | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes |
| Jing, J., 202050 | Unclear | Yes | Yes | Yes | Yes | Yes | Yes | Yes |
| Huang, H. Y., 201754 | Unclear | Unclear | Yes | Yes | Yes | No | Yes | Yes |
| Lei, H., 202051 | Unclear | Unclear | Yes | Yes | Yes | No | Yes | Yes |
| Liao, X. Z., 201849 | Yes | Unclear | Yes | Yes | Yes | No | Yes | Yes |
| Zhang, K., 202055 | Unclear | Unclear | Yes | Yes | Yes | No | Yes | Yes |
| Su, M., 202052 | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes |
| Yu, H. H., 202153 | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes |
| Zhang, X., 201744 | Unclear | Unclear | NA | Yes | NA | NA | Yes | Yes |
| Wu, Q., 202047 | Yes | Unclear | Yes | Yes | Yes | Yes | Yes | Yes |
| Mao, W., 201743 | Unclear | Unclear | NA | Yes | NA | NA | Yes | Yes |
| Leng, A., 201946 | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes |
| Zheng, A., 201845 | Unclear | Unclear | Yes | Yes | Yes | Yes | Yes | Yes |
| Xu, R. H., 202056 | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes |
| Chen, S., 202039 | Unclear | Unclear | Yes | Yes | Yes | Yes | Yes | Unclear |
| Xu, H., 201938 | Yes | Unclear | Unclear | Yes | Yes | Yes | Yes | Yes |
| Liu, S., 201737 | Unclear | Unclear | Yes | Yes | Yes | Yes | Yes | Yes |
| Wang, C., 201636 | Unclear | Unclear | Yes | Yes | Yes | Yes | Yes | Unclear |
| Wu, X., 201535 | Unclear | Unclear | Yes | Yes | Yes | No | Yes | Yes |
| Kang, Y., 201534 | Unclear | Unclear | Yes | Yes | Yes | Yes | Yes | Yes |
| Peng, H., 201333 | Unclear | Unclear | NA | Yes | NA | NA | Yes | Yes |
| Huang, H., 201232 | Unclear | Unclear | NA | Yes | NA | NA | Yes | Yes |
| Huang, H., 201231 | Unclear | Unclear | Yes | Yes | Yes | Yes | Yes | Yes |
| Zeng, Q., 201130 | Unclear | Unclear | NA | Yes | NA | NA | Yes | Yes |
| Luo, R., 200629 | Unclear | Unclear | Yes | Yes | Yes | Yes | Yes | Yes |
| Xiao, S., 201040 | Unclear | Unclear | Yes | Yes | Yes | Yes | Yes | Yes |
| Shang, M., 201341 | Yes | Unclear | Yes | Yes | Yes | Yes | Yes | Unclear |
| Yao, N., 201942 | Yes | Yes | NA | Yes | NA | NA | Yes | Yes |
| Sun, C.Y., 202159 | Yes | Unclear | Yes | Yes | Yes | Yes | Yes | Yes |
| Sun, C.Y., 202158 | Yes | Unclear | Yes | Yes | Yes | Yes | Yes | Yes |
| Fu, W., 202157 | Yes | Unclear | Yes | Yes | Yes | Yes | Yes | Yes |
NA, not applicable.