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

Abstract

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.

Figure 1

Evolution of outbreaks Plots show the number of care homes with a first positive test for SARS-CoV-2 infection, according to current testing policy (A), the 7-day rolling average of all tests and PCR-confirmed cases (B), and detected incidence of COVID-19 by number of care home beds (C). SARS-CoV-2=severe acute respiratory syndrome coronavirus 2.

Figure 2

Patterns of outbreak for 69 care homes with an outbreak

Figure 3

Deaths of care home residents in care homes and in hospital Plots show deaths of residents in care homes with a confirmed COVID-19 outbreak (A), in care homes without an outbreak (B), and in hospitals (C). Data obtained from NRS death registrations. Data are by week of registration (which is later than date of death). NRS data are provisional and could be subject to change, particularly later data if registration was delayed. NRS=National Records of Scotland.