Risk factors for outbreaks of COVID‐19 in care homes following hospital discharge: A national cohort analysis

  1. Chris Emmerson
  2. James P. Adamson
  3. Drew Turner
  4. Mike B. Gravenor
  5. Jane Salmon
  6. Simon Cottrell
  7. Victoria Middleton
  8. Buffy Thomas
  9. Brendan W. Mason
  10. Chris J. Williams

Reviewed by

Read the full article

Listed in

Log in to save this article

Abstract

Background

The population of adult residential care homes has been shown to have high morbidity and mortality in relation to COVID‐19.

Methods

We examined 3115 hospital discharges to a national cohort of 1068 adult care homes and subsequent outbreaks of COVID‐19 occurring between 22 February and 27 June 2020. A Cox proportional hazards regression model was used to assess the impact of time‐dependent exposure to hospital discharge on incidence of the first known outbreak, over a window of 7‐21 days after discharge, and adjusted for care home characteristics, including size and type of provision.

Results

A total of 330 homes experienced an outbreak, and 544 homes received a discharge over the study period. Exposure to hospital discharge was not associated with a significant increase in the risk of a new outbreak (hazard ratio 1.15, 95% CI 0.89, 1.47, P  = .29) after adjusting for care home characteristics. Care home size was the most significant predictor. Hazard ratios (95% CI) in comparison with homes of <10 residents were as follows: 3.40 (1.99, 5.80) for 10‐24 residents; 8.25 (4.93, 13.81) for 25‐49 residents; and 17.35 (9.65, 31.19) for 50+ residents. When stratified for care home size, the outbreak rates were similar for periods when homes were exposed to a hospital discharge, in comparison with periods when homes were unexposed.

Conclusion

Our analyses showed that large homes were at considerably greater risk of outbreaks throughout the epidemic, and after adjusting for care home size, a discharge from hospital was not associated with a significant increase in risk.

Article activity feed

  1. ScreenIT

    SciScore for 10.1101/2020.08.24.20168955: (What is this?)

    Please note, not all rigor criteria are appropriate for all manuscripts.

    Table 1: Rigor

    NIH rigor criteria are not applicable to paper type.

    Table 2: Resources

    No key resources detected.

    Results from OddPub: We did not detect open data. We also did not detect open code. Researchers are encouraged to share open data when possible (see Nature blog).

    Results from LimitationRecognizer: We detected the following sentences addressing limitations in the study:
    Limitations: Clearly not all discharges would have had COVID-19, so the effect of our defined risk factor would be diluted by non-risk discharges. However, the aim was to see an overall effect of the pattern and policy of discharges. It was not possible to ascertain if the case in outbreaks was the resident who had been discharged from hospital within the period of interest, and this will be the focus of further investigation. The matching of cases to discharges could be investigated to assess if a case was the primary case discharged from hospital or a secondary infection within the home. Further study will focus on understanding how many homes care home staff worked in during the study period, especially if agency staff were working across multiple homes each week. Here, we focused on the timing of the first outbreak. An analysis of the timeline of all cases is complicated by very limited information on the balance of internal and external exposure, as well as changing testing practices. Such an analysis could shed light on the time-dependent intensity of cases, and what external factors may have been contributing to that. Conclusions and recommendations: Larger homes were at considerably greater risk of COVID-19 outbreaks, but for the period studied, the risk was not significantly increased in the period following a hospital discharge. Further analyses should investigate the risk where discharges were confirmed or probable cases of COVID-19, and also consider additional ev...

    Results from TrialIdentifier: No clinical trial numbers were referenced.

    Results from Barzooka: We did not find any issues relating to the usage of bar graphs.

    Results from JetFighter: We did not find any issues relating to colormaps.

    Results from rtransparent:
    • Thank you for including a conflict of interest statement. Authors are encouraged to include this statement when submitting to a journal.
    • Thank you for including a funding statement. Authors are encouraged to include this statement when submitting to a journal.
    • No protocol registration statement was detected.

    About SciScore

    SciScore is an automated tool that is designed to assist expert reviewers by finding and presenting formulaic information scattered throughout a paper in a standard, easy to digest format. SciScore checks for the presence and correctness of RRIDs (research resource identifiers), and for rigor criteria such as sex and investigator blinding. For details on the theoretical underpinning of rigor criteria and the tools shown here, including references cited, please follow this link.

  2. Version published to 10.1111/irv.12831
  3. Version published to 10.1101/2020.08.24.20168955v1 on medRxiv