Study design
Data were obtained as part of a multicentre observational study: COPE (COVID-19 in Older People study). The study was authorised by the Health Research Authority (20/HRA/1898) in the UK and the Ethics Committee of Policlinico Hospital Modena (Reference 369/2020/OSS/AOUMO) in Italy. The full study details can be found within the COPE protocol [17], and the main study findings are reported elsewhere [9]. This manuscript follows the STROBE statement for reporting of cohort studies. Investigators carried out standardisation training in both data collection and CFS assessment. A central MACRO database, hosted by King’s Clinical Trials Unit (KCTU), was used to enter data centrally.
Setting
The COPE-Discharge study used an established network of twelve UK sites and one Italian site. The UK centres included Ysbyty Ystrad Fawr in Caerphilly, Royal Gwent Hospital in Newport, Nevill Hall Hospital in Abergavenny, University Hospital of Wales in Cardiff, Southmead Hospital in Bristol, Aberdeen Royal Infirmary, Royal Alexandra Hospital in Paisley, Inverclyde Royal Hospital, Salford Royal Hospital, Glasgow Royal Infirmary, Maidstone Hospital, and Ysbyty Gwynedd in Bangor. The Italian centre was the University Hospital of Modena Policlinico.
Participants
Each site research team screened hospital admission lists daily. The ethical approval was such that formal written consent from participants was deemed as not being required as all data were routinely collected in hospital records.
Inclusion/exclusion criteria
The study included consecutive hospitalised patients aged 18 years or older with a confirmed diagnosis of COVID-19 admitted between 27 February and 10 June 2020; diagnostic criteria included laboratory-confirmed SARS-CoV-2-positive swab or a clinical diagnosis of COVID-19 based on signs, symptoms, and supporting radiology. Patients were excluded due to missing care level at admission and discharge, were not discharged from hospital, and that died prior to discharge.
Outcome
The primary outcome was increased care needs at discharge. Care was recorded as an ordinal variable, with seven levels of increasing dependence care needs: at home without formal carers, own home with carers (formal or informal), intermediate care, increased number of daily carer visits, sheltered care, residential home, and nursing home.
The number of daily carer visits required by patients was measured at admission and discharge. Sheltered care was the accommodation of private independent units with shared facilities such as gardens and lounges and a warden on site. Residential care was defined as 24-h supported care managed by non-nursing trained care staff. Nursing care comprised service users receiving 24-h support from nursing staff, requiring assistance with most personal daily activities, or support with complex physical and/or psychological needs. Intermediate care varied depending on local provision and was defined as short-term care (either in an institution or individual’s home) designed to facilitate the transition from hospital to home [18, 19]. Intermediate care services develop person-centred goals aimed at optimising independence and well-being of individuals through collaborative multidisciplinary holistic assessment and interventions.
Covariates
Demographic and clinical characteristics recorded at admission were age, sex, smoking status (never, previous, or current), C-reactive protein (CRP) as a marker of disease severity, estimated glomerular filtration rate (eGFR), previous history of coronary artery disease (CAD), diabetes mellitus, chronic obstructive pulmonary disease (COPD), and hypertension (no, yes not on treatment, and yes on treatment).
Frailty was scored based on a functional status history from 2 weeks prior to admission and was measured using the Clinical Frailty Scale (CFS). The CFS is a 9-point score, from 1 being very fit, 2 well, 3 managing well, 4 living with very mild frailty, 5 living with mild frailty, 6 living with moderate frailty, 7 living with severe frailty, 8 living with very severe frailty, and 9 terminally ill but otherwise living with severe frailty [13]. For the purpose of the analyses, CFS categories 1–3 were grouped and used as a reference group. In each site, the assessment of CFS in patients was undertaken by clinical teams comprising a combination of consultant geriatricians, emergency physicians, and intensive care consultants. For all COVID-19 patients admitted to hospital, the CFS was documented in a dedicated section on the admission notes. To safeguard data quality, each principal investigator ensured adequate knowledge within the data collection team of frailty scoring.
Statistical analysis
We analysed the change in care level using a mixed-effects logistic regression, fitted with a random effect model to account for variation occurring at each hospital site. Care level was associated with baseline frailty and adjusted for patient age group (< 65, 65–79, ≥ 80 years old), sex, smoking status (never smoker, ex-smoker, current smoker), CRP (≥ 40 mg/L taken as abnormal), diabetes (no/yes), hypertension (no/yes/yes and on treatment), coronary artery disease (no/yes), and reduced renal function (eGFR < 60, ≥ 60 mL/min/1.73 m2). Both crude odds ratios (OR) and adjusted odds ratios (aOR) were calculated with 95% confidence intervals (95% CI). The analysis was carried out using Stata version 15.
We carried out a sensitivity analysis to assess longer-term increased dependence by excluding patients that were discharged with intermediate care.