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Evaluation of the quality of the included studies in this meta-analysis using Quality Index
| First author | Year | Quality score component | Score | ||||
|---|---|---|---|---|---|---|---|
| I | II | III | IV | V | Over all | ||
| Li(a) | 2014 | 10 | 3 | 4 | 3 | 5 | 25 |
| Wei | 2013 | 9 | 3 | 4 | 2 | 5 | 23 |
| Demirok | 2013 | 9 | 3 | 4 | 4 | 5 | 25 |
| Gao | 2014 | 9 | 3 | 4 | 2 | 5 | 23 |
| Li(b) | 2013 | 10 | 3 | 4 | 3 | 5 | 25 |
I: Reporting; II: External Validity; III: Bias; IV: Confounding; V: Power
