Effectiveness of 3 Versus 6 ft of Physical Distancing for Controlling Spread of Coronavirus Disease 2019 Among Primary and Secondary Students and Staff: A Retrospective, Statewide Cohort Study

Background. National and international guidelines differ about the optimal physical distancing between students for prevention of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission; studies directly comparing the impact of >= 3 versus >= 6 ft of physical distancing policies in school settings are lacking. Thus, our objective was to compare incident cases of SARS-CoV-2 in students and staff in Massachusetts public schools among districts with different physical distancing requirements. State guidance mandates masking for all school staff and for students in grades 2 and higher; the majority of districts required universal masking. Methods. Community incidence rates of SARS-CoV-2, SARS-CoV-2 cases among students in grades K-12 and staff participating in-person learning, and district infection control plans were linked. Incidence rate ratios (IRRs) for students and staff members in traditional public school districts with >= 3 versus >= 6 ft of physical distancing were estimated using log-binomial regression; models adjusted for community incidence are also reported. Results. Among 251 eligible school districts, 537 336 students and 99 390 staff attended in-person instruction during the 16-week study period, representing 6 400 175 student learning weeks and 1 342 574 staff learning weeks. Student case rates were similar in the 242 districts with >= 3 versus >= 6 ft of physical distancing between students (IRR, 0.891; 95% confidence interval, .594-1.335); results were similar after adjustment for community incidence (adjusted IRR, 0.904; .616-1.325). Cases among school staff in districts with >= 3 versus >= 6 ft of physical distancing were also similar (IRR, 1.015, 95% confidence interval, .754-1.365). Conclusions. Lower physical distancing requirements can be adopted in school settings with masking mandates without negatively affecting student or staff safety.

Automated summary

The study compared incident cases of SARS-CoV-2 in students and staff in Massachusetts public schools with different physical distancing requirements, and found similar case rates among districts with different physical distancing policies. This suggests that lower physical distancing requirements can be implemented in schools with masking mandates without compromising student or staff safety.