Table 1.
Summary characteristics and descriptions for the included studies that investigated frailty and COVID‐19‐related mortality
| Author, country | Setting | Study type | Study period (DD/MM/YY) | Sample size, proportion male (%) | Age, mean (SD) (years) | Proportion Caucasian (%) | Frailty measure; proportion frail (%) | COVID‐19 diagnosis | Comments | NOS grading |
|---|---|---|---|---|---|---|---|---|---|---|
| Aliberti, 1 Brazil | COVID‐19 special hospital | Retrospective cohort study | 30/03/20 to 7/07/20 | 1830 (57) | 66 (11) | N/R | CFS†; 25 | RT‐PCR | Although patients were followed up at 6 months, only 30‐day follow up was included in this study | 7 (fair) |
| Apea, 2 UK | Acute hospitals (5 in UK) | Prospective Cohort study | 1/01/20 to 13/05/20 | 1996 (60.6) | 63.4 (18.3) | 35.2 | HFRS; 47.9 | RT‐PCR | The primary outcome was 30‐day mortality from time of first hospital admission with COVID‐19 diagnosis | 8 (good) |
| Aw, 3 UK | Acute hospital | Cohort study | 8/03/20 to 30/04/20 | 677 (61) | 62.2 (17.4) | 35 | CFS; 71.3 | RT‐PCR |
The follow‐up period was the time between admission and death, discharge or 28 days Censored at 28 days from hospitalisation |
6 (fair) |
| Baker, 4 UK | Acute hospital | Retrospective cohort study | 8/01/20 to 12/04/20 | 316 (55) | 72.7 (17.1) | 96 | CFS; N/R | RT‐PCR | Censored at 28 days from hospitalisation | 6 (poor) |
| Bellelli, 5 Italy | General hospital | Cohort study | 27/02/20 to 7/04/20 | 105 (68.6) | N/R | N/R | FI; N/R | RT‐PCR | Follow up at 48 days | 6 (poor) |
| Brill, 6 UK | Acute hospital | Retrospective cohort study | 9/03/20 to 6/04/20 | 410 (35) | 81.1 (8.1) | 60 | CFS; N/R | RT‐PCR | Censored at 28 days from hospitalisation | 6 (fair) |
| Chinnadurai, 7 UK | Acute hospital | Cohort study | 23/03/20 to 30/04/20 | 215 (62) | 72.0 (16.4) | 87 | CFS; 51.2 | RT‐PCR | Censored at 14 days from hospitalisation | 7 (fair) |
| Davis, 8 UK | Acute hospital | Retrospective cohort study | 18/03/20 to 20/04/20 | 222 (33) | 82 (range 56–99) | N/R | CFS; 75 | RT‐PCR | Reported 30‐day mortality post hospitalisation | 6 (poor) |
| De Smet, 9 Belgium | General hospital | Retrospective cohort study | 12/03/20 to 30/04/20 | 81 (41) | 70.3 (20.1) | N/R | CFS; 79.5 | RT‐PCR | − | 6 (poor) |
| Dres, 10 France, Switzerland Belgium | ICU | Prospective cohort study | 25/02/20 to 04/05/20 | 1199 (73) | 74.7 (4.4) | N/R | CFS; 9 | RT‐PCR |
Follow up at 28 days Mortality was 60% at 90 days |
8 (good) |
| Fagard, 11 Belgium | Acute hospital | Retrospective cohort study | 16/03/20 to 16/05/20 | 105 (52.4) | 81.7 (8.3) | N/R | CFS; 59 | RT‐PCR | In hospital mortality | 7 (fair) |
| Hendra, 12 UK | Acute hospital with four satellite dialysis units | Retrospective cohort study | 11/03/20 to 10/05/20 | 148 (56.8) | 64.1 (14.6) | 32.4 | CFS | RT‐PCR | Follow up censored on 26 May 2020 | 8 (good) |
| Hewitt, 13 Italy/UK | Acute hospital (UK 10, Italy 1) | Cohort study | 27/02/20 to 30/04/20 | 1564 (58) | 76.0 (5.2) | N/R | CFS; 35 | RT‐PCR/clinical | Patients still in hospital at follow‐up point were censored for the time‐to‐mortality analysis. Censored at 28 days from hospitalisation | 7 (fair) |
| Hoek, 14 Netherlands | Acute hospital | Cohort study | 27/02/20 to 30/04/20 | 23 (78) | 60.7 (15.0) | 61 | CFS; ~22 | RT‐PCR | Reported on in hospital mortality | 4 (poor) |
| Knights, 15 UK | General hospital | Retrospective cohort study | 01/03/20 to 31/03/20 | 108 (61) | 69.3 (16.3) | 76 | CFS; N/R | RT‐PCR | In hospital deaths included patients discharged for palliative care either at home or a local palliative care inpatient unit | 7 (fair) |
| Koduri, 16 UK | Acute hospital | Retrospective cohort study | 20/02/20 to 07/05/20 | 500 (60) | 87.6 | CFS; 42.9 | RT‐PCR | − | 6 (poor) | |
| Kokosz‐Bargiel, 17 Poland | Acute hospital and ICU | Retrospective cohort study | 10/03/20 to 10/06/20 | 67 (32 ICU) (69) | 62.4 (10.4) | N/R | CFS; 55 | RT‐PCR | − | 5 (poor) |
| Kundi, 18 Turkey | All acute hospitals in Turkey | Retrospective cohort study | 11/03/20 to 22/06/20 | 18 234 (46.6) | 74.1 (7.4) | N/R | HFRS; 67.4 | RT‐PCR | In hospital all‐cause mortality | 7 (fair) |
| Maguire, 19 UK | General hospital | Retrospective cohort study | 17/03/20 to 01/05/20 | 224 (55) | Most >70 | 93.3 | CFS; 46 | RT‐PCR/clinical | Censored at 30 days from hospitalisation | 7 (fair) |
| Marengoni, 20 Italy | COVID‐19 special hospital | Retrospective cohort study | 08/03/20 to 14/04/20 | 165 (61) | 69.3 (14.5) | N/R | CFS; 15.2 | RT‐PCR/clinical | To death or discharge. Maximum 40 days | 7 (fair) |
| Osuafor, 21 UK | Acute hospital | Retrospective cohort study | 01/03/20 to 15/05/20 | 214 (55.1) | 80.7 (8.9) | 83.2 | CFS; 66.4 | RT‐PCR | Follow up at 45 days | 7 (fair) |
| Owen, 22 UK | Acute hospital | Retrospective observational study | 23/01/20 to 13/03/20 | 301 (56) | 68.7 (15.6) | N/R | CFS; 43.8 | RT‐PCR/clinical |
The primary outcome was time to death (all‐cause mortality). Deaths occurring outside the hospital were captured daily Censored at 30 days of hospitalisation |
6 (poor) |
| Steinmeyer, 23 France | Acute hospital | Retrospective cohort study | 13/03/20 to 04/05/20 | 94 (45) | 85.5 (7.5) | N/R |
FIND 76.6 dependent 10.6 frail |
RT‐PCR | Patients were followed up from hospital admission to hospital discharge or death | 5 (poor) |
| Tehrani, 24 Sweden | Acute hospital | Retrospective cohort study | 05/03/20 to 28/04/20 | 255 (59) | 66.0 (17.0) | N/R | CFS; 50 | RT‐PCR | Follow up at 60 days | 7 (fair) |
| Welch, 25 UK, USA, Italy Libya, Egypt, Iraq, Saudi Arabia, Spain, Greece, Sudan, Turkey, Cyprus | 55 acute hospitals | Cohort study | 01/02/20 to 31/05/20 | 5711 (55.1) | 71.7 (18.8) | N/R | CFS; 42.8 | RT‐PCR | Censored at 30 days from hospitalisation | 8 (good) |
Only five patients had a CFS score of 9.
CFS, clinical frailty score; FI, frailty index; FIND, frail non‐disabled survey; HFRS, hospital risk frailty score; ICU, intensive care unit; NOS, Newcastle−Ottawa Quality Assessment Score; N/R, not reported; RT‐PCR, reverse transcription−polymerase chain reaction.
NOS study quality.
Good quality: 3 or 4 stars in selection domain AND 1 or 2 stars in comparability domain AND 2 or 3 stars in outcome/exposure domain.
Fair quality: 2 stars in selection domain AND 1 or 2 stars in comparability domain AND 2 or 3 stars in outcome/exposure domain.
Poor quality: 0 or 1 star in selection domain OR 0 stars in comparability domain OR 0 or 1 stars in outcome/exposure domain.