School-Based COVID-19 Case Growth Rates in the US, What a Crowdsourced Dataset Can Tell Us

Importance: Different reopening plans were implemented to bring students back to schools in anticipation of schoolrelated COVID-19 outbreaks.The hybrid reopening plan was considered a medium-risk option to mitigate greater risk than in-person and remote reopening plans.In the absence of an official in-school transmission surveillance system and the relevant data, whether hybrid reopening plan could protect students and decrease in-school transmission rates remains unknown.Objective: To estimate the case growth rates of the school districts chose remote and hybrid reopening plans compared with those chose in-person reopening plans.Design, setting, and participants: Using a validated crowdsourced dataset maintained by the National Education Association, we grouped 742 school districts in 49 states reopened between August 10, 2020 and November 12, 2020 into hybrid (46%), remote (15%), and in-person (40%) reopening plans.We used a retrospective cohort design with the three reopening plans as the exposures to assess area-risk factors and the COVID-19 case growth rates by different reopening plans. Main outcomes and measures:Factors associated with choosing remote, hybrid, and in-person reopening plans and the case growth rates among the three reopening plans.Results: School districts with a low proportion of white students, a high background risk, in an urban county, or with a Democratic governor, were more likely to choose remote or hybrid than in-person reopening plans.With the in-person reopening plan in referent, the odds ratios of the case growth rates for remote and hybrid reopening plan were 0.988 (95% CI: 0.986-0.989)and 1.014 (95% CI: 1.013-1.015),respectively.The consistent results were found among school districts with a high background risk.Conclusions: School districts reopened with the hybrid reopening plan had higher case growth rates among low and high background risk areas than those reopened with the in-person plan.In-person reopening plan may be a better option than hybrid reopening plan as far as the COVID-19 case growth rates in the beginning of the semester are concerned.