Risk factors associated with SARS-CoV-2 infection and outbreaks in Long Term Care Facilities in England: a national survey
Authors: Shallcross Laura , Burke Danielle , Stat Owen Abbott C , Donaldson Alasdair , Hallatt Gemma , Hayward Andrew , Hopkins Susan , Krutikov Maria , Sharp Katie , Wardman Leone , Thorne Sapphira 
Published: October 2020

Background

Outbreaks of SARS-CoV-2 have occurred worldwide in Long Term Care Facilities (LTCFs), but the reasons why some facilities are particularly vulnerable to infection are poorly understood. We aimed to identify risk factors for SARS-CoV-2 infection and outbreaks in LTCFs.

Methods

Cross-sectional survey of all LTCFs providing dementia care or care to adults >65 years in England with linkage to SARS-CoV-2 test results. Exposures included: LTCF characteristics, staffing factors, and use of disease control measures. Main outcomes included risk factors for infection and outbreaks, estimated using multivariable logistic regression, and survey and test-based weighted estimates of SARS-CoV-2 prevalence.

Findings

5126/9081 (56%) LTCFs participated in the survey, with 160,033 residents and 248,594 staff. The weighted period prevalence of infection in residents and staff respectively was 10.5% (95% CI: 9.9-11.1%) and 3.8% (95%: 3.4-4.2%) and 2724 LTCFs (53.1%) had ≥1 infection. Odds of infection and/or outbreaks were reduced in LTCFs that paid sickness pay, cohorted staff, did not employ agency staff and had higher staff to resident ratios. Higher odds of infection and outbreaks were identified in facilities with more admissions, lower cleaning frequency, poor compliance with isolation and “for profit” status.

Interpretation

Half of LTCFs had no cases suggesting they remain vulnerable to outbreaks. Reducing transmission from staff requires adequate sick pay, minimal use of temporary staff, improved staffing ratios and staff cohorting. Transmission from residents is associated with the number of admissions to the facility and poor compliance with isolation.

Funding

UK Government Department of Health & Social Care

Research in context

Evidence before this study

COVID-19 outbreaks have occurred worldwide in long-term care facilities (LTCFs), which provide care to elderly and vulnerable residents, and are associated with high mortality. The reasons why LTCFs are particularly vulnerable to COVID-19 are poorly understood. Most studies of risk factors for COVID-19 to date have been limited by scale, and poor quality administrative, demographic and infection control data. We conducted a systematic search on 27 July 2020 in MEDLINE Ovid, WHO COVID-19 database and in MedRxiv to identify studies reporting risk factors for COVID-19 infection or outbreaks in LTCFs, with no date or language restrictions. We used the search terms “COVID-19”, “SARS-CoV-2”, “coronavirus” and “care home”, “nursing home”, “long term care facilit” and excluded studies that did not investigate LTCF-level risk factors. 14 studies met our inclusion criteria comprising 11 cross-sectional studies and 3 surveys. The largest cross-sectional study was conducted in 9395 specialised nursing facilities across 30 states in USA; the largest survey was conducted in 124 LTCFs in Haute-Garrone region of France. Risk of bias was high across all studies, and results could not be pooled due to heterogeneity between studies. Main risk factors for infection and/or outbreaks related to the size of the facility, lower ratios of staff to residents, urban location, higher occupancy, and the community prevalence of infection. Only one study collected data on the use of disease control measures during the pandemic, and no studies provided data on risk factors such as the use of temporary staff, or the impact of staff working across multiple locations.

Added value of this study

We conducted a national telephone survey with managers of all LTCFs in England which provided dementia care or care to residents aged > 65 years to collect data on the number of staff and residents in each facility, confirmed SARS-CoV-2 infections, characteristics of the facility e.g.size, staffing (use of temporary staff, staffing ratios, sickness pay) and disease control measures such as cohorting and isolation. We identified risk factors for infection in residents and staff, outbreaks (defined as ≥1 case per LTCF) and large outbreaks using logistic regression. We also estimated the proportion of staff and residents who had been infected with SARS-CoV-2. Responses were obtained from 5126 of out 9081 (56%) of eligible LTCFs. To our knowledge, this is the largest and most detailed survey of risk factors for SARS-CoV-2 infection and outbreaks that has been conducted in LTCFs.

Implications of all the available evidence

Almost half of LTCFs surveyed in this study did not report any cases of infection, and remain vulnerable to infection and outbreaks, highlighting the need for effective control measures. Reducing transmission from staff requires adequate sick pay, minimal use of temporary staff, improved staffing ratios and staff cohorting. Transmission from residents is associated with the number of admissions to the facility and poor compliance with control measures such as isolation.