Association between school closure and COVID-19 incidence, mortality

Editor's Note

This study found a temporal association between school closures statewide and lower COVID-19 incidence and mortality, but some of the reductions may have been related to other concurrent interventions.

At the time of school closure, the incidence of COVID-19 ranged from 0 to 14.75 cases per 100,000 population.

Closure was associated with a significant decline in the incidence of COVID-19 (adjusted relative change per week, -62%) and mortality (adjusted relative change per week, -58%).

In a model derived from this analysis, researches estimated that closing schools when the cumulative incidence of COVID-19 was in the lowest quartile compared with the highest quartile was associated with 128.7 fewer cases per 100,000 over 26 days and with 1.5 fewer deaths per 100,00 over 16 days.

However, the degree to which the associations with school closure relate to decreased spread of COVID-19 by children or a combination of child and adult factors is unclear. If the primary effect associated with school closure is related to altered adult behavior, and not children spreading the virus to adults, the primary lag period used in these analyses should be adjusted, the researchers say.