Table 2.
Methodological quality of the included studies according to the risk of bias 2.0.
| Author | Year | D1 | D2 | D3 | D4 | D5 | Overall |
|---|---|---|---|---|---|---|---|
| Che | 2004 | Sc | Sc | L | H | Sc | H |
| Chen | 2004 | Sc | Sc | L | Sc | Sc | Sc |
| Xu | 2005 | Sc | Sc | L | Sc | Sc | Sc |
| Liu | 2006 | Sc | Sc | L | H | Sc | H |
| Chen | 2007 | Sc | Sc | L | H | Sc | H |
| Huang | 2007 | L | L | L | L | Sc | Sc |
| Zeng | 2009 | L | Sc | L | Sc | Sc | Sc |
| Cao | 2010 | Sc | Sc | L | Sc | Sc | Sc |
| He | 2010 | Sc | Sc | L | H | Sc | H |
| Hua | 2010 | Sc | Sc | L | H | Sc | H |
| Luo | 2010 | Sc | Sc | L | Sc | Sc | Sc |
| Yu | 2010 | Sc | Sc | L | H | Sc | H |
| Liu | 2011 | Sc | Sc | L | H | Sc | H |
| Lu | 2011 | Sc | Sc | L | Sc | Sc | Sc |
| Tian | 2011 | L | Sc | L | Sc | Sc | Sc |
| Xu | 2011 | Sc | Sc | L | Sc | Sc | Sc |
| Yao | 2011 | L | Sc | L | Sc | Sc | Sc |
| Zheng | 2011 | Sc | Sc | L | Sc | Sc | Sc |
| Jiang | 2012 | L | L | L | L | Sc | Sc |
| Liu | 2012 | Sc | Sc | L | Sc | Sc | Sc |
| Xie | 2012 | Sc | Sc | L | H | Sc | H |
| Zhang | 2012 | Sc | Sc | L | Sc | Sc | Sc |
| Zhou | 2012a | Sc | Sc | L | Sc | Sc | Sc |
| Zhou | 2012b | Sc | Sc | L | H | Sc | H |
| Chen | 2013 | Sc | Sc | L | Sc | Sc | Sc |
| Ding | 2013 | Sc | Sc | L | Sc | Sc | Sc |
| Mo | 2013 | Sc | Sc | L | Sc | Sc | Sc |
| Song | 2013 | Sc | Sc | L | Sc | Sc | Sc |
| Zhang | 2013 | Sc | Sc | L | Sc | Sc | Sc |
| Cheng | 2014 | Sc | Sc | L | Sc | Sc | Sc |
| Du | 2014 | Sc | Sc | L | Sc | Sc | Sc |
| Li | 2014 | Sc | Sc | L | Sc | Sc | Sc |
| Liang | 2014 | Sc | Sc | L | Sc | Sc | Sc |
| Liu | 2014 | Sc | Sc | L | Sc | Sc | Sc |
| Qiu | 2014 | Sc | Sc | L | Sc | Sc | Sc |
| Zhang | 2014a | Sc | Sc | L | Sc | Sc | Sc |
| Zhang | 2014b | Sc | Sc | L | Sc | Sc | Sc |
| Zhang | 2014c | Sc | Sc | L | Sc | Sc | Sc |
| Cai | 2015 | Sc | Sc | L | Sc | Sc | Sc |
| Jin | 2015a | Sc | Sc | L | Sc | Sc | Sc |
| Jin | 2015b | Sc | Sc | L | Sc | Sc | Sc |
| Lu | 2015a | Sc | Sc | L | H | Sc | H |
| Lu | 2015b | Sc | Sc | L | Sc | Sc | Sc |
| Ma | 2015 | Sc | Sc | L | Sc | Sc | Sc |
| Peng | 2015 | Sc | Sc | L | Sc | Sc | Sc |
| Sun | 2015 | Sc | Sc | L | Sc | Sc | Sc |
| Wang | 2015a | Sc | Sc | L | Sc | Sc | Sc |
| Wang | 2015b | L | Sc | L | H | Sc | H |
| Wang | 2015c | Sc | Sc | L | Sc | Sc | Sc |
| Yuan | 2015 | Sc | Sc | L | H | Sc | H |
| Zhang | 2015a | L | Sc | L | Sc | Sc | Sc |
| Zhang | 2015b | L | Sc | L | Sc | Sc | Sc |
| Zhang | 2015c | L | Sc | L | Sc | Sc | Sc |
| Chen | 2016 | Sc | Sc | L | Sc | Sc | Sc |
| He | 2016a | Sc | Sc | L | H | Sc | H |
| He | 2016b | Sc | Sc | L | Sc | Sc | Sc |
| Jiang | 2016 | Sc | Sc | L | Sc | Sc | Sc |
| Shan | 2016 | L | Sc | L | H | Sc | H |
| Wang | 2016a | Sc | Sc | L | H | Sc | H |
| Wang | 2016b | Sc | Sc | L | H | Sc | H |
| Wu | 2016 | Sc | Sc | L | Sc | Sc | Sc |
| Xie | 2016 | L | Sc | L | Sc | Sc | Sc |
| Xu | 2016 | Sc | Sc | L | H | Sc | H |
| Yang | 2016a | Sc | Sc | Sc | H | Sc | H |
| Yang | 2016b | L | Sc | L | Sc | Sc | Sc |
| Yu | 2016 | Sc | Sc | L | H | Sc | H |
| Cao | 2017 | L | Sc | L | L | Sc | Sc |
| Cheng | 2017 | Sc | Sc | L | Sc | Sc | Sc |
| Ding | 2017 | L | Sc | L | Sc | Sc | Sc |
| Du | 2017 | Sc | Sc | L | Sc | Sc | Sc |
| Feng | 2017 | L | Sc | L | Sc | Sc | Sc |
| Han | 2017a | Sc | Sc | L | Sc | Sc | Sc |
| Han | 2017b | Sc | Sc | L | Sc | Sc | Sc |
| Li | 2017 | Sc | Sc | L | H | Sc | H |
| Liu | 2017 | Sc | Sc | L | Sc | Sc | Sc |
| Luo | 2017 | Sc | Sc | L | H | Sc | H |
| Pang | 2017 | Sc | Sc | L | Sc | Sc | Sc |
| Shi | 2017 | Sc | Sc | L | Sc | Sc | Sc |
| Song | 2017 | Sc | Sc | L | Sc | Sc | Sc |
| Wang | 2017 | Sc | Sc | L | Sc | Sc | Sc |
| Wu | 2017 | Sc | Sc | L | H | Sc | H |
| Yang | 2017 | L | Sc | L | Sc | Sc | Sc |
| Zeng | 2017 | Sc | Sc | L | Sc | Sc | Sc |
| Zhang | 2017a | Sc | Sc | L | Sc | Sc | Sc |
| Zhang | 2017b | Sc | Sc | L | Sc | Sc | Sc |
| Zhang | 2017c | Sc | Sc | L | Sc | Sc | Sc |
| Zhang | 2017d | Sc | Sc | L | Sc | Sc | Sc |
| Zhang | 2017e | Sc | Sc | L | Sc | Sc | Sc |
| Zhao | 2017 | Sc | Sc | L | H | Sc | H |
| Chai | 2018 | Sc | Sc | L | Sc | Sc | Sc |
| Li | 2018 | L | Sc | L | Sc | Sc | Sc |
| Liu | 2018 | Sc | Sc | L | Sc | Sc | Sc |
| Luo | 2018 | Sc | Sc | L | Sc | Sc | Sc |
| Ma | 2018a | L | Sc | L | Sc | Sc | Sc |
| Ma | 2018b | Sc | Sc | L | Sc | Sc | Sc |
| Xiao | 2018 | L | Sc | L | Sc | Sc | Sc |
| Xie | 2018 | Sc | Sc | L | Sc | Sc | Sc |
| Zhang | 2018a | Sc | Sc | L | Sc | Sc | Sc |
| Zhang | 2018b | L | Sc | L | Sc | Sc | Sc |
| Zhou | 2018 | Sc | Sc | L | Sc | Sc | Sc |
| Chen | 2019 | Sc | Sc | L | Sc | Sc | Sc |
| Ge | 2019 | Sc | Sc | L | Sc | Sc | Sc |
| Han | 2019 | Sc | Sc | L | H | Sc | H |
| Hu | 2019 | L | Sc | L | Sc | Sc | Sc |
| Lu | 2019 | L | Sc | L | L | Sc | Sc |
| Xun | 2019 | Sc | Sc | L | Sc | Sc | Sc |
| Yang | 2019 | Sc | Sc | L | Sc | Sc | Sc |
| Yao | 2019 | L | Sc | L | Sc | Sc | Sc |
| Zhong | 2019 | Sc | Sc | L | Sc | Sc | Sc |
| Chen | 2020 | Sc | Sc | L | H | Sc | H |
| Hao | 2020 | L | Sc | L | Sc | Sc | Sc |
| Ji | 2020 | Sc | Sc | L | Sc | Sc | Sc |
| Liu | 2020a | Sc | Sc | L | Sc | Sc | Sc |
| Liu | 2020b | Sc | Sc | L | Sc | Sc | Sc |
| Lu | 2020 | Sc | Sc | L | Sc | Sc | Sc |
| Qu | 2020 | L | Sc | L | Sc | Sc | Sc |
| Ren | 2020 | Sc | Sc | L | Sc | Sc | Sc |
| Shen | 2020 | Sc | Sc | L | Sc | Sc | Sc |
| Wu | 2020 | Sc | Sc | L | Sc | Sc | Sc |
| Yang | 2020 | Sc | Sc | L | Sc | Sc | Sc |
| Zheng | 2020 | Sc | Sc | L | Sc | Sc | Sc |
| Jin | 2021 | Sc | Sc | L | Sc | Sc | Sc |
| Lan | 2021 | Sc | Sc | L | Sc | Sc | Sc |
| Le | 2021 | Sc | Sc | L | Sc | Sc | Sc |
| Tang | 2021 | L | Sc | L | Sc | Sc | Sc |
| Wang | 2021 | Sc | Sc | L | Sc | Sc | Sc |
D1–D5: 5 domain criteria; D1, bias arising from the randomization process; D2, bias due to deviations from intended interventions; D3, bias due to missing outcome data; D4, bias in the measurement of the outcome; D5, bias in the selection of the reported results; H: high risk of bias; L: low risk of bias; Sc: some concerns.