Table 1.
Characteristics of studies included in the meta-analysis
| Author | Study Design | Country | Age (years) | Sample size (Severe) | Sample size (Mild) | Sample size | Sex (male %) |
|---|---|---|---|---|---|---|---|
| Chen G. 2020 [3] | Retrospective | China | 56 (50–65) | 11 | 10 | 21 | 17 (81%) |
| Chen R. 2020 [31] | Retrospective | China | 56 ± 15 | 155 | 345 | 500 | 313 (57.1%) |
| Chi Y. 2020 [10] | Retrospective | China | 46 | 8 | 22 | 30 | / |
| Du R. 2020 [9] | Prospective | China | 69 ± 8 | 21 | 42 | 63 | 30 (47.6%) |
| He R. 2020 [6] | Retrospective | China | 49 (34–62) | 69 | 135 | 204 | 79 (38.7%) |
| Jiang M. 2020 [12] | Retrospective | China | 46 (17–88) | 17 | 86 | 103 | 58 (56.3%) |
| Li S. 2020 [24] | Retrospective | China | 46 | 26 | 43 | 69 | 40 (60.0%) |
| Liu Y. 2020 [32] | Retrospective | China | / | 30 | 46 | 76 | / |
| Ma J. 2020 [33] | Retrospective | China | 62 (59–70) | 17 | 20 | 37 | 20 (54%) |
| Pallotto C. 2020 [34] | Retrospective | Italy | 65 | 13 | 25 | 38 | 19 (50.0%) |
| Qin C. 2020 [4] | Retrospective | China | 58 (47–67) | 27 | 17 | 44 | 235 (52%) |
| Sophie H. 2020 [5] | Retrospective | France | 66 | 38 | 36 | 74 | 60 (81.1%) |
| Sun D. 2020 [15] | Retrospective | China | 65 | 11 | 25 | 36 | 29 (80.5%) |
| Urra J.M. 2020 [35] | Retrospective | Spain | 59 | 27 | 145 | 172 | 104 (60.5%) |
| Wan S. 2020 [13] | Retrospective | China | 46 | 21 | 102 | 123 | 66 (53.7%) |
| Wang F. 2020 [18] | Retrospective | China | 69 ± 9 | 14 | 14 | 28 | 21 (75%) |
| Zhang J. 2020 [19] | Retrospective | China | 38 (32–57) | 93 | 18 | 111 | 46 (41.4%) |
| Zhao Y. 2020 [7] | Retrospective | China | 48 | 18 | 53 | 71 | 30 (42.3%) |
| Zheng Y. 2020 [36] | Retrospective | China | 49 | 26 | 63 | 89 | / |
| Zhou Y. 2020 [14] | Retrospective | China | 42 | 5 | 12 | 17 | 6 (35.3%) |
| Zhu Z. 2020 [16] | Retrospective | China | 51 | 111 | 16 | 127 | 45 (35.4%) |
Age is described as mean or mean ± SD or median (IQR)