Emerging evidence: Rapid review of risk factors associated with COVID-19 outbreaks and mortality in long-term care facilities and what strategies mitigate risk?

Full report:

National Collaborating Centre for Methods and Tools. (2020, October 16). What risk factors are
associated with COVID-19 outbreaks and mortality in long-term care facilities and what
strategies mitigate risk?
School of Nursing, McMaster University (Canada).

Summary:

Rapid review by the National Collaborating Centre for Methods and Tools based at the School of Nursing at McMaster University, including evidence available up to 5th of October 2020. This summary aims to provide a brief overview of the findings.

The authors note that this review included many emerging studies that have not been peer-reviewed and caution is advised when using and interpreting the evidence. The authors appraised the quality of evidence for each study included. As all studies included were observational, they provide low quality evidence. Particularly for the studies rated as “very low certainty”, it is likely that the findings will change as more evidence accumulates.

Research question:

What risk factors are associated with COVID-19 outbreaks and mortality in LTC facilities and what strategies mitigate risk?

Key findings:
Risk factors associated with COVID-19 outbreaks and mortality in LTC facilities:
  • Incidence in the surrounding community was found to have the strongest association with COVID-19 infections in LTC settings (moderate certainty)
  • Resident level factors (low certainty):
    • Association with COVID-19 infections, outbreaks and mortality: racial/ethnic minority status, older age, male sex, receipt of Medicaid or Medicare
    • Association with infections and outbreaks but not mortality: severity of impairment
  • Organisational level factors (low certainty):
    • Registered nursing staffing was associated with reduced risk of infections, outbreaks and mortality
    • For-profit status and facility size/density were consistently associated with increased risk of infections, outbreaks and mortality

The authors highlight that the associations observed in some of the studies were not adjusted by community transmission, and that the large variations observed between geographic regions could be explained by variations in community transmission.

Large variations in the potential factors included in the studies and the way in which these were measured makes comparisons between studies difficult and also makes it difficult to compare the strength of the relationships observed between studies.

Facility size was consistently associated with increased risk of infections and mortality, but it is unclear whether this is due to the absolute number of residents or beds, or to density of residents within the facility, or the ratio of residents to staff.

What strategies mitigate risk of outbreaks and mortality within LTC?
  • Most guideline recommendations include: surveillance, monitoring and evaluation of staff and resident symptoms, and use of personal protection equipment (PPE). The certainty of the evidence is low.
  • Other interventions demonstrating some effect include promotion of hand washing, enhanced cleaning measures, social distancing, and cohorting (low certainty).
  • Technological platforms or tools show potential for decreased transmission (through case and/or contact identification), but certainty of evidence is very low.
  • No evidence was found related to visitor restriction policies.
  • Most studies did not address potential confounding factors.

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