Table 1 .
Summary characteristics of retained studies examining frailty and COVID-19-related outcomes
| Author | Country | Setting | Sample size | Age, mean (SD) *unless otherwise stated | Proportion female (%) | Proportion white (%) | Frailty measure | COVID diagnosis | NOS grading |
|---|---|---|---|---|---|---|---|---|---|
| Apea [16] | UK | Five acute hospitals | 1996 | 62.2 (17.4) | 39 | 35 | CFS | PCR | 6 |
| Aw [21] | UK | Acute hospital | 677 | 81.1 (8.1) | 46 | 81 | CFS | PCR | 6 |
| Baker [22] | UK | Acute hospital | 316 | 72.7 (17.1) | 45 | 96 | CFS | PCR | 6 |
| Brill [23] | UK | Acute hospital | 410 | 81.1 (8.1) | 65 | 60 | CFS | PCR | 4 |
| Chinnadurai [24] | UK | Acute hospital | 215 | 72.0 (16.4) | 38 | 87 | CFS | PCR | 5 |
| Cobos-Siles [25] | Spain | Acute hospital | 656 | 82.7 (10.5) | 43 | Not stated | CFS | PCR | 6 |
| Conway [26] | UK | Acute hospital | 71 | 70.7 (16.6) | 42 | 99 | CFS | PCR | 4 |
| Crespo [10] | Spain | Renal transplant cohort, acute hospital | 16 | 59.7 (12.6) | 6 | Not stated | Fried | PCR | 4 |
| Davis [27] | UK | Acute hospital | 222 | 82 (range 56–99) | 67 | Not stated | CFS | PCR | 5 |
| De Smet [28] | Belgium | General hospital | 81 | 70.3 (20.1) | 59 | Not stated | CFS | PCR | 6 |
| Doglietto [11] | Italy | Patients with COVID undergoing surgery | 41 | 82.7 (10.5) | 56 | Not stated | CFS | PCR | 4 |
| Frost [29] | UK | Seven acute hospitals | 749 | 85.3 (6.8) | 32 | Not stated | CFS | PCR | 6 |
| Hagg [17] | Sweden | Acute hospital | 250 | 81.0 (8.6) | 52 | Not stated | CFS/HFRS | PCR/clinical | 7 |
| Hewitt [18] | Italy/UK | 11 acute hospitals (10 England, 1 Italy) | 1,564 | 76.0 (5.2) | 42 | Not stated | CFS | PCR/clinical | 6 |
| Hoek [30] | The Netherlands | Multi-centre—solid organ transplant recipients | 23 | 60.7 (15.0) | 22 | 61 | CFS | PCR | 4 |
| Knights [31] | UK | General hospital | 108 | 69.3 (16.3) | 39 | 76 | CFS | PCR | 7 |
| Kundi [15] | Turkey | All acute hospitals in Turkey | 18,234 | 74.1 (7.4) | 53.4 | Not stated | HFRS | PCR | 7 |
| Marengoni [12] | Italy | COVID-19 special hospital | 165 | 69.3 (14.5) | 39 | Not stated | CFS | PCR/clinical | 7 |
| Mendes [13] | Switzerland | COVID-19 special hospital | 235 | 86.3 (6.5) | 57 | 100 | CFS | PCR/clinical | 6 |
| Miles [32] | UK | Acute hospital | 217 | 59 | 38 | Not stated | CFS | PCR | 6 |
| Owen [19] | UK | Acute hospital | 301 | 68.7 (15.6) | 44 | Not stated | CFS | PCR/clinical | 6 |
| Poco [14] | Brazil | COVID-19 special hospital | 711 | 66 (−) | 43 | Not stated | CFS | PCR/clinical | 6 |
| Rawle [33] | UK | Acute hospital | 134 | 80.0 (6.8) | 46 | 76 | CFS | PCR | 4 |
| Steinmeyer [20] | France | Acute hospital | 94 | 85.5 (7.5) | 55 | Not stated | FIND | PCR | 5 |
| Tehrani [34] | Sweden | Acute hospital | 255 | 66 (17) | 41 | Not stated | CFS (7 point scale) | PCR | 7 |
| Thompson [35] | UK | Acute hospital | 470 | 78.8 (8.3) | 46 | 83 | CFS | PCR | 6 |