OBJECTIVE: A Canadian health authority implemented a multi-sectoral intervention designed to control SARS-CoV-2 transmission during long term care facility (LTCF) outbreaks . The primary objective was to evaluate the effectiveness of the intervention 14 days after implementation .
DESIGN: Quasi-experimental, segmented regression analysis . INTERVENTION: A series of outbreak measures classified into four categories: case/contact management, proactive case detection, rigorous infection control practices and resource prioritization/stewardship .
METHODS: A mixed-effects segmented Poisson regression model was fitted to the incidence rate of COVID-19, calculated every two days, within each facility and case type (staff vs. residents). For each facility, the outbreak time period was segmented into an early outbreak period (within 14 days intervention) and post-intervention period (after 14 days from intervention). Model outputs quantified COVID-19 incidence trend and rate changes between these two periods . A secondary model was constructed to identify effect modification by case type .
RESULTS: The significant upward trend in COVID-19 incidence rate during the early outbreak period (RR=1.07 , 95% CI : 1.03-1.11, p-value <0.001) reversed during the post-intervention period (RR=0.73 , 95% CI : 0.67-0.80, p-value <0.001). The average trend did not differ by case type during early outbreak (p-value> 0.05) or post-intervention (p-value> 0.05) periods . However, staff had a 70% larger decrease in the average rate of COVID-19 during the post-intervention period compared to residents (RR=0.30 , 95% CI : 0.10- 0.88, p-value <0.05).
CONCLUSIONS: Our study provides evidence for the effectiveness of this intervention to reduce the transmission of COVID-19 in LTCF . This intervention can be adapted and utilized by other jurisdictions to protect the vulnerable individuals in LTCFs.