Table 1.
Basic study and patients characteristics
| Authors | Year | Country | Study design | Study quality* | COVID-19 patients | Age of COVID-19 patients (years) | Male percentage in COVID-19 patients |
|---|---|---|---|---|---|---|---|
| Chen et al. | 2020 | China | Retrospective single center | Fair |
Overall: 50 non-severe: 15 (30%) severe: 23 (46%) critical: 12 (24%) |
NR | NR |
| Gao et al. | 2020 | China | Retrospective single center | Fair |
Overall: 100 non-severe: 34 (34%) severe/critical: 66 (66%) |
Mean: 62 | 52% |
| Khoo et al. | 2020 | UK | Prospective single center | Fair | Overall: 334 | Mean: 66 | 61% |
| Lania et al. | 2020 | Italy | Retrospective single center | Fair | Overall: 287 | Median: 66 | 67% |
| Lui et al. | 2020 | China | Prospective single center | Fair |
Overall: 191 non-severe: 185 (97%) severe. 6 (3%) |
Mean: 53.5 | 52% |
| Muller et al. | 2020 | Italy | Prospective single center | Fair |
Overall: 126 non-severe: 41 (33%) severe: 85 (67%) |
Mean: 65 and 70 in two groups | 61% |
| Zou et al. | 2020 | China | Retrospective single center | Fair | Overall: 149 | Median: 47 | 48% |
* = according to the National Heart, Lung and Blood Institute quality assessment tools; NR not reported