COVID-19 Outbreaks in Washington State K-12 Schools: Time to first COVID-19 school outbreak characterized by learning modality and community transmission

Abstract

BACKGROUND: There is limited research available on COVID-19 outbreaks in K-12 schools, and many schools will be looking for guidance on safely keeping schools open for the 2021-2022 school year. The primary purpose of this study was to examine the relationship between learning modality and time to assess whether there was a relationship between community level transmission and time to COVID-19 outbreak in schools. METHODS: This study used data from the Washington State Department of Health (DOH) School Outbreak Assessment of Policies and Practices (SOAPP) survey. This is a retrospective survey designed to learn about school outbreaks and to assess the effectiveness of certain COVID-19 mitigation measures in reducing transmission in the K-12 school setting. A time-to-event analysis using the Cox Proportional Model was conducted in order to compare the time to the first outbreak between different learning modalities. Time to outbreak was compared between outbreaks in 100% remote, remote with exceptions, hybrid, and traditional in-person settings. Secondary analyses included community transmission of COVID-19 in the Cox Proportional Model. RESULTS: The time-to-event analysis for the first aim did not find an association between learning modality and time to first COVID-19 outbreak. This The Cox Proportional Hazards model for the second aim met all assumptions and flagged hybrid learning modality and low transmission rate as significantly associated with time to outbreak. The p-value for hybrid learning modality was 0.008 with a hazard ratio of 4.46 (95% CI: 1.86, 10.70), indicating a strong relationship between a hybrid learning modality and increased risk of an outbreak. The p-value for low transmission rate was 0.0015 with a hazard ratio of 3.73 (95% CI: 1.65, 8.40), indicating a strong relationship between a low transmission rate and shorter time to outbreak. CONCLUSIONS: Further research is needed to draw conclusions about the relationships between learning modality, community level transmission of COVID-19 and outbreaks in K-12 schools in Washington state.