Study suggests 3 feet sufficient for physical distancing in schools
Results from a study of 251 Massachusetts school districts suggest that maintaining a physical distance of 3 feet in schools may be safe, “provided other mitigation measures, such a as universal masking, are implemented,” researchers said.
Data from the study showed no significant difference in case rates among schools that implemented a 3-feet distancing rule vs. schools that implemented a 6-feet rule.
The CDC recommends physical distancing of at least 6 feet in schools, but that could change. A federal official told CNN that the agency is reviewing the data to see if a change is necessary. The CDC did not immediately respond to several messages from Healio about whether it was considering an update to the guidance, which was published just last month.
In the study, Polly van den Berg, MD, an infectious disease fellow at Beth Israel Deaconess Medical Center in Boston, and colleagues calculated COVID-19 incidence rate ratios for the 251 K-12 school districts — which included 537,336 students and 99,390 staff — during a 16-week period from Sept. 24, through Jan. 7.
According to the report, there were 279 Massachusetts school districts with detailed infection control plans. Of these, 266 districts were open for any type of in-person learning during the study period. The researchers excluded districts that remained fully remote until Nov. 1. Nine districts were excluded because they allowed intermediate distancing between 4 and 5 feet. Two districts were excluded for allowing 3 feet of distance in some grades but 6 feet in others. However, another two districts were excluded for having contradictory distancing policies.
Of the districts included in the study, 98% had the same infection control policy, and all of them had universal masking in grades 2 and above. There were 48 districts with a minimum requirement of 3 feet of physical distancing, and 194 requiring at least 6 feet.
For the entire 16-week study period, 4,226 cases of COVID-19 occurred among students, and 2,382 among staff.
Of the districts that implemented a required distance of at least 3 feet, there were 895 cases of COVID-19 among students and 431 among staff. Districts requiring at least 6 feet of distance reported 3,223 cases in students and 2,382 in staff (unadjusted incidence rate ratio [IRR] = 0.891; 95% CI, 0.594-1.335).
When the authors adjusted for community incidence, they calculated a similar risk between the two distances for students (IRR = 0.904; 95% CI, 0.616-1.325) and staff (IRR = 1.015; 95% CI, 0.754-1.365).
“Our finding of no significant difference in student or staff case rates between schools with at least 3 feet vs. at least 6 feet of distancing with a large sample size suggests that the lower physical distancing recommendation can be adopted in school settings without negatively impacting safety,” the authors wrote.