The effect of frailty on survival in patients with COVID-19 (COPE): a multicentre, European, observational cohort study

Background: The COVID-19 pandemic has placed unprecedented strain on health care systems. Frailty is being used in clinical decision making for patients with COVID-19, yet the prevalence and effect of frailty in people with COVID-19 is not known. The Cope Study (COVID-19 in Older People) was an observational cohort study designed to address this evidence gap. Methods: All adults, regardless of age, admitted consecutively with COVID-19 from 10 UK and one Italian hospital had demographic and diagnostic data collected. Frailty was assessed using the Clinical Frailty Score (CFS). The primary endpoint was in-hospital mortality (time to mortality and 7 day mortality) and time to discharge as the secondary outcome. Data were gathered between 27th February and 28th of April 2020. Data was analysed with a mixed-effects, Cox proportional hazards and Logistic regression models. Findings: Data were collected on 1564 people with a confirmed diagnosed of COVID-19: median age was 74 years old (IQR, 61-83), 901 were male (57.7%), 425 (27.2%) died in hospital. Using the Clinical Frailty Scale, the number of people who were classed as mildly frail or above was 51.1%. Both time to mortality and time to discharge worsened with increasing frailty, after adjustment for: age; sex; smoking; and comorbidities. The adjusted Hazard Ratio (aHR, 95%CI) for CFS 3-4 (managing well, vulnerable), 5-6 (mildly frail and frail) and 7-9 (severely frail, very severely frail and terminally ill) compared to CFS 1-2 (very fit, well) were 1.64 (1.06-2.55), 2.02 (1.27-3.20) and 2.66 (1.68-4.21) for time to mortality and 0.97 (0.79-1.19), 0.69 (0.53-0.89) and 0.63 (0.47-0.83) for the time to discharge. Interpretation: In a large adult population of people with COVID-19, worsening frailty was associated with progressively increasing mortality and later discharge from hospital. These data provide evidence that frailty is not dependent on age and that the Clinical Frailty Scale can inform decision making about medical care in the adult COVID-19 hospital population.