Top 5 Takeaways

1. Lower Incidence with Masks: Districts with universal mask requirements had a 23% lower incidence of COVID-19 among staff and students compared to those without mask mandates.
2. Impact of Mask Policies: The study found that mask policies were effective in reducing COVID-19 incidence, particularly in areas with high community transmission.
3. Comparative Analysis: Districts that switched from no mask policy to any mask policy saw a significant decrease in COVID-19 incidence among students and staff.
4. Observed-to-Expected Ratios: Ratios of observed-to-expected cases were lower in districts with full or partial mask policies compared to those with no mask policies.
5. Community and School Incidence: COVID-19 incidence among students and staff was consistently higher than in the surrounding community, highlighting the importance of in-school preventive measures.

Original Article Author and Citation

Corresponding Author

Catherine V. Donovan, phz2@cdc.gov

Suggested Citation

Donovan CV, Rose C, Lewis KN, et al. SARS-CoV-2 Incidence in K–12 School Districts with Mask-Required Versus Mask-Optional Policies — Arkansas, August–October 2021. MMWR Morb Mortal Wkly Rep 2022;71:384–389. DOI: http://dx.doi.org/10.15585/mmwr.mm7110e1

Summary

This study examined the impact of mask policies on COVID-19 incidence in K–12 school districts in Arkansas from August to October 2021. Districts with universal mask requirements had significantly lower COVID-19 incidence among students and staff compared to districts without mask mandates. The study used multiple analytical approaches to assess the association between mask policies and COVID-19 incidence, adjusting for factors such as community transmission rates and vaccination coverage.

Methods

Data were collected from various sources, including the Arkansas Department of Health’s COVID-19 surveillance database and immunization registry. The study compared COVID-19 incidence rates in districts with full, partial, or no mask requirements. Incidence rate ratios (IRRs), observed-to-expected case ratios, and comparative interrupted time series models were used to analyze the data. Adjustments were made for community transmission rates, vaccination coverage, and socioeconomic status.

Discussion

The findings indicate that mask policies in schools are effective in reducing COVID-19 incidence, particularly in areas with moderate to substantial community transmission. The study’s strengths include the use of multiple analytical methods and sensitivity analyses, which consistently showed the protective effect of mask use. Limitations include the inability to account for other preventive measures and differences in quarantine rules between schools with and without mask mandates.

Conclusion

Mask policies in K–12 schools are associated with lower COVID-19 incidence among students and staff. Masks should be considered a crucial part of a multicomponent strategy to prevent COVID-19, especially in areas with high community transmission levels.

This has been your booster shot of MMWR Info! Please check back for more MMWR, Public Health, and Programming Tutorial content daily.