Association of Frailty With Mortality in Older Inpatients With Covid-19

A Cohort Study

Darren Aw; Lauren Woodrow; Giulia Ogliari; Rowan Harwood


Age Ageing. 2020;49(6):915-922. 

In This Article


We examined all adult admissions with COVID-19 from 1 March 2020 to 30 April 2020. Ethical approval was not required as the analysis entailed use of anonymised routinely collected data; audit office governance approval was obtained (project number 20–208C).

We identified patients who were admitted and diagnosed with COVID-19 in the presence of clinical symptoms and by a positive real time reverse transcriptase-polymerase chain reaction (RT-PCR) nasopharyngeal swab test, by radiological diagnosis, or by clinical criteria as decided by the responsible clinician. Radiological evidence of COVID-19 was defined by a chest radiograph or computed tomography of the chest showing classical signs.[10,11] Clinical diagnosis was reached in patients with a new continuous cough or fever and/or new desaturation requiring supplemental oxygen and/or haematological and/or radiological findings suggestive of COVID-19. Clinical judgement was applied for those who presented with atypical features, particularly among older patients.[12]

Demographic and clinical data were retrieved from computer systems including Medway Live, NerveCentre and Unity Digital Health Records.


Ethnicity is routinely recorded based on the categories by the Census of UK (2011), which we recategorised as: white British or Irish; ethnic minorities (African descent, Asian descent, any other ethnic group and any mixed background, white—other); unknown or not stated.


From each patient's postcode, we estimated deprivation by the index of multiple deprivation (IMD) quintile. The IMD is a small area-level index, which takes into account income, employment, education, health, crime, barriers to housing and services and living environment, and forms the official measure of relative deprivation in the UK.[13,14] The higher the quintile, the less deprived.

National Early Warning Score 2

We retrieved the admission National Early Warning Score 2 (NEWS-2) for each patient. NEWS-2 is a trigger score for clinical deterioration and is a proxy for the severity of acute illness based on a patient's clinical observations. It includes respiratory rate, oxygen saturations, systolic blood pressure, pulse rate, level of consciousness or confusion and temperature. The higher the NEWS-2 score, the more severe the illness of the patient.[15]


The CFS score is widely used to stratify older adults into different levels of frailty.[9] CFS score should reflect the baseline frailty 2 weeks prior to admission to the hospital for acute illness. Frontline clinicians within our hospital have been trained to score CFS, using pictorial diagrams, since 2016. Most CFS scores were attributed by the admitting clinician, within the Emergency Department, and then gathered from Medway Live. The remaining were assigned retrospectively by a doctor experienced in using the scale, using a combination of medical, physiotherapy and occupational therapist notes. Insufficient information was collected to identify CFS scores in 13 patients (1.9%). We categorised all patients into these frailty categories, based on CFS scores: CFS 1–3 (including 'very fit', 'well' and 'managing well'), CFS 4 ('vulnerable'), CFS 5 ('mildly frail'), CFS 6 ('moderately frail'), CFS 7–9 (including 'severely frail', 'very severely frail' and 'terminally ill').

We retrieved all elective, emergency and day-case admissions in 2019 for each patient, and categorised these as none versus one or more.


All-cause mortality was obtained from electronic hospital records. The follow-up period was the time between admission and death, discharge or 28 May 2020. For those patients who died in hospital, we retrieved the cause of death from the death certificate. We categorised the deaths that occurred in hospital as COVID-19 deaths versus non-COVID-19 deaths.