Evolution and effects of COVID-19 outbreaks in care homes: a population analysis in 189 care homes in one geographical region of the UK

BACKGROUND: COVID-19 has affected care home residents internationally, but detailed information on outbreaks is scarce. We aimed to describe the evolution of outbreaks of COVID-19 in all care homes in one large health region in Scotland. METHODS: We did a population analysis of testing, cases, and deaths in care homes in the National Health Service (NHS) Lothian health region of the UK. We obtained data for COVID-19 testing (PCR testing of nasopharyngeal swabs for severe acute respiratory syndrome coronavirus 2 [SARS-CoV-2]) and deaths (COVID-19-related and non-COVID-19-related), and we analysed data by several variables including type of care home, number of beds, and locality. Outcome measures were timing of outbreaks, number of confirmed cases of COVID-19 in care home residents, care home characteristics associated with the presence of an outbreak, and deaths of residents in both care homes and hospitals. We calculated excess deaths (both COVID-19-related and non-COVID-19-related), which we defined as the sum of deaths over and above the historical average in the same period over the past 5 years. FINDINGS: Between March 10 and Aug 2, 2020, residents at 189 care homes (5843 beds) were tested for COVID-19 when symptomatic. A COVID-19 outbreak was confirmed at 69 (37%) care homes, of which 66 (96%) were care homes for older people. The size of care homes for older people was strongly associated with a COVID-19 outbreak (odds ratio per 20-bed increase 3·35, 95% CI 1·99–5·63). 907 confirmed cases of SARS-CoV-2 infection were recorded during the study period, and 432 COVID-19-related deaths. 229 (25%) COVID-19-related cases and 99 (24%) COVID-related deaths occurred in five (3%) of 189 care homes, and 441 (49%) cases and 207 (50%) deaths were in 13 (7%) care homes. 411 (95%) COVID-19-related deaths occurred in the 69 care homes with a confirmed COVID-19 outbreak, 19 (4%) deaths were in hospital, and two (<1%) were in one of the 120 care homes without a confirmed COVID-19 outbreak. At the 69 care homes with a confirmed COVID-19 outbreak, 74 excess non-COVID-19-related deaths were reported, whereas ten non-COVID-19-related excess deaths were observed in the 120 care homes without a confirmed COVID-19 outbreak. 32 fewer non-COVID-19-related deaths than expected were reported among care home residents in hospital. INTERPRETATION: The effect of COVID-19 on care homes has been substantial but concentrated in care homes with known outbreaks. A key implication from our findings is that, if community incidence of COVID-19 increases again, many care home residents will be susceptible. Shielding care home residents from potential sources of SARS-CoV-2 infection, and ensuring rapid action to minimise outbreak size if infection is introduced, will be important for any second wave. FUNDING: None.