Table 1.
Baseline characteristics of the included studies
| References | Study design | Sample size (n) | Mean age (years) | Male (%) | HT (%) | DM (%) | CKD (%) | Lymphocytes (109) | D-dimer (mcg/ml) | Outcome | Cut-off for Thrombocytopenia (*109/l) | NOS |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| [8] | PO | 373 | 52.78 | 67 | – | – | – | – | – | Mortality | <150 | 7 |
| [9] | PO | 178 | 64 | 59.6 | 32.6 | 17.4 | 1.7 | 1.2 | 0.56 | Severity | <100 | 7 |
| [20] | RO | 21 | 56 | 81 | 23.8 | 14.3 | – | 0.9 | 0.5 | Severity | <100 | 7 |
| [24] | RO | 44 | >65 (56.8) | 36.3 | 34.1 | 15.9 | – | – | – | Severity | <150 | 7 |
| [25] | RO | 393 | 62.2 | 60.6 | 50.1 | 25.2 | – | – | Dimer >0.5 (36.4) | IMV | <150 | 6 |
| [26] | RO | 1099 | 47 | 59.1 | 15 | 7.4 | 0.7 | 1 | Dimer >0.5 (46.4) | Severity | <150 | 7 |
| [27] | RO | 98 | 55.4 | 38.8 | 30.6 | 9.2 | – | 1.4 | – | ICU Care | ? | 7 |
| [28] | RO | 41 | 49 | 73 | 15 | 20 | – | 0.8 | 0.5 | ICU Care | <100 | 6 |
| [29] | RO | 110 | 56.9 | 43.6 | 33.6 | 26.4 | – | 1.4 | 4.4 Dimer >0.5 (76.3) | Severity | <140 | 9 |
| [30] | RO | 59 | 64 | 49 | 42 | 15 | – | 1.1 | 6.1 | ICU Care | <100 | 7 |
| [10] | RO | 63 | 48 | 85 | 32 | 32 | 6.4 | 1.1 | 0.6 Dimer >0.55 (59) | ICU Care | <125 | 6 |
| [23] | RO | 611 | 64 | 54 | 30 | 16 | 1 | 1.24 | Severity | <100 | 7 | |
| [11] | RO | 548 | 60 | 50.9 | 30.3 | 15.1 | 1.8 | - | – | Severity | <150 | 9 |
| [12] | RO | 1190 | 57 | 53.4 | 26.1 | 12.2 | 2.6 | 1.2 | 0.9 | Mortality | <100 | 9 |
| [13] | RO | 756 | 69 | 62.2 | 37.8 | 28.6 | 13.5 | Dimer >0.50 (87.8) | Mortality | <130 | 9 | |
| [14] | RO | 113 | 53.8 | 62.8 | 19.5 | 14.2 | 5.3 | 1.2 | – | Mortality | <150 | 7 |
| [15] | RO | 135 | 47 | 53.3 | 9.6 | 8.9 | – | 1.1 | 0.4 | Severity | <125 | 7 |
| [16] | RO | 276 | 51 | 56.2 | 17 | 5.1 | – | 1.1 | Dimer >0.50 (53.7) | Severity | <150 | 7 |
| [17] | RO | 239 | 62.5 | 59.8 | 43.9 | 18.4 | – | 0.6 | – | Mortality | <125 | 9 |
| [18] | RO | 1476 | 58.7 | 52.3 | – | – | – | – | – | Mortality | <125 | 8 |
| [19] | RO | 788 | 45.8 | 51.6 | 16 | 7.2 | 0.9 | 1.2 | – | Severity | <100 | 9 |
| [21] | RO | 161 | 45 | 49.7 | 13.7 | 4.3 | 1.1 | – | Severity | <100 | 7 | |
| [22] | RO | 191 | 56 | 62 | 30 | 19 | 1 | 1 | 0.8 Dimer >0.50 (68) | Mortality | <100 | 7 |
CKD, chronic kidney disease; DM, diabetes mellitus; HT, hypertension; ICU, intensive care unit; IMV, invasive mechanical ventilation; PO, prospective observational; RO, retrospective observational; NOS, Newcastle−Ottawa scale.