Erratum: Vol. 70, No. 6

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The report “Decline in COVID-19 Hospitalization Growth Rates Associated with Statewide Mask Mandates — 10 States, March–October 2020” contained several errors.

On page 212, in the first paragraph, the fifth sentence should have read “After mask mandates had been implemented for ≥3 weeks, hospitalization growth rates declined by 5.6 percentage points among persons aged 18–39 years (95% CI = 0.9–10.4) and those aged 40–64 years (95% CI = 1.0–10.2).”

On page 213, in the first complete paragraph of the right-hand column, the second sentence should have read “The overall COVID-19–associated hospitalization growth rates among all adults declined 2.4 percentage points (p-value = 0.04) <3 weeks after the implementation week and declined 5.0 percentage points (p-value <0.01) during the period ≥3 weeks after the implementation week (Table 2).”

On pages 213–214, the second complete paragraph of the right-hand column should have read “Among persons aged 18–39 years, the hospitalization growth rates <3 weeks after the implementation week were lower than were those during the <4 weeks before the implementation week and the implementation week (reference period) when no mask mandate existed, but the estimated percentage point difference (–2.2) was not statistically significant (p-value = 0.30) (Figure) (Table 2). However, in this population, mask mandates were associated with a statistically significant 5.6 percentage-point decline in COVID-19 hospitalization growth rates (p-value = 0.02) ≥3 weeks after the implementation week. Among adults aged 40–64 years, mask mandates were associated with a 2.9 percentage-point reduction in COVID-19 hospitalization growth rates (p-value = 0.03) <3 weeks after the implementation week. Hospitalization growth rates declined by 5.6 percentage points (p-value = 0.02) during ≥3 weeks after the implementation week. Among adults aged ≥65 years, COVID-19 hospitalization growth rates declined <3 weeks after the implementation week (1.2 percentage points) and ≥3 weeks after the implementation week (0.7 percentage points); however, the declines were not statistically significant.”

On page 214, there were multiple errors in Table 2. The corrected table is as follows:

On page 215, the second paragraph of the Summary should have read “During March 22October 17, 2020, 10 sites participating in the COVID-19–Associated Hospitalization Surveillance Network in states with statewide mask mandates reported a decline in weekly COVID-19–associated hospitalization growth rates by up to 5.6 percentage points for adults aged 18–64 years after mandate implementation, compared with growth rates during the 4 weeks preceding implementation of the mandate.”

The Supplementary Table (https://stacks.cdc.gov/view/cdc/101127) should have listed the date of statewide reopening for Michigan as June 1, 2020.

TABLE 2. Estimated association between mask mandates and COVID-19–associated hospitalization growth rates in sites with statewide mask mandates, by age group — 10 COVID-19–Associated Hospitalization Surveillance Network sites,*,† March–October 2020Return to your place in the text
Time relative to week mask mandate was implemented All (≥18 yrs) 18–39 yrs 40–64 yrs ≥65 yrs
Percentage point change* (95% CI) p-value Percentage point change* (95% CI) p-value Percentage point change* (95% CI) p-value Percentage point change* (95% CI) p-value
≥4 weeks before −4.3 (−10.6 to 1.9) 0.17 −4.8 (−17.0 to 7.5) 0.43 −4.0 (−13.3 to 5.3) 0.38 −5.3 (−15.0 to 4.4) 0.27
<4 weeks before§ Referent Referent Referent Referent
<3 weeks after −2.4 (−4.7 to −0.1) 0.04 −2.2 (−6.4 to 2.1) 0.30 −2.9 (−5.5 to −0.3) 0.03 −1.2 (−3.9 to 1.5) 0.38
≥3 weeks after −5.0 (−8.6 to −1.4) <0.01 −5.6 (−10.4 to −0.9) 0.02 −5.6 (−10.2 to −1.0) 0.02 −0.7 (−5.3 to 3.9) 0.76

Abbreviations: CI = confidence interval; COVID-19 = coronavirus disease 2019.
* Percentage points are coefficients from the regression models. Reported numbers are from regression models, which controlled for state, age group, time (week), and statewide closing and reopening.
California, Colorado, Connecticut, Maryland, Michigan, Minnesota, New Mexico, New York, Ohio, and Oregon.
§ This period includes the implementation week (i.e., week zero).


Suggested citation for this article: Erratum: Vol. 70, No. 6. MMWR Morb Mortal Wkly Rep 2021;70:293. DOI: http://dx.doi.org/10.15585/mmwr.mm7008a4external icon.

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