Effectiveness of three versus six feet of physical distancing for controlling spread of COVID-19 among primary and secondary students and staff: A retrospective, state-wide cohort study
March 10, 2021
Polly van den Berg, MD, Elissa M Schechter-Perkins, MD, MPH, Rebecca S Jack, MPP, Isabella Epshtein, MPP, Richard Nelson, PhD, Emily Oster, PhD, Westyn Branch-Elliman, MD, MMSc
Clinical Infectious Diseases
The authors analyzed COVID-19 incidence based on different physical distancing requirements in schools using publicly available data to compare SARS-CoV-infection among students and staff in Massachusetts public schools participating in in-person learning. Data for 279 districts was collected from USAFacts and the Massachusetts Department of Elementary and Secondary Education from September 24th, 2020 to January 27th, 2021. Among the 251 eligible districts, 537,336 students and 99,390 staff attended in-person. All schools had mask mandates for all staff and students enrolled in grade 2 or higher. Throughout the study period, 4,226 cases were reported in students and 2,382 in school staff. Case rates among students were similar when comparing districts with ≥3 feet recommendations (895 cases) versus ≥6 feet recommendations (3,223 cases); after controlling for community incidence rates, the adjusted incidence rate ratio (IRR) was 0.904, (95% CI, 0.616-1.325). Similarly, after controlling for community incidence the authors found cases among staff were similar across schools with ≥3 feet recommendations (431 cases) and ≥6 feet recommendations (2,382 cases) (adjusted IRR, 1.015, 95% CI, 0.754-1.365). These results suggest that lower physical distancing recommendations can be implemented in schools with mask mandates without increasing risk of SARS-CoV-2 transmission.
van den Berg P, Schechter-Perkins EM, Jack RS, et al. Effectiveness of three versus six feet of physical distancing for controlling spread of COVID-19 among primary and secondary students and staff: A retrospective, state-wide cohort study. Clin Infect Dis 2021; published online March. DOI:10.1093/cid/ciab230.