Date: June 7 2021
Summary: How mask mandates were associated with decreases in COVID hospitalization growth rates
Keywords: #hospitalization #covid #policy #mask #mandates #decrease #archive
H. Joo et al., "Decline in COVID-19 Hospitalization Growth Rates Associated with Statewide Mask Mandates — 10 States, March–October 2020," MMWR Morb. Mortal. Wkly. Rep., vol. 70, no. 6, pp. 212–216, Feb. 2021, doi: 10.15585/mmwr.mm7006e2.
Examined whether implementation of statewide mask mandates was associated with COVID-19–associated hospitalization growth rates among different age groups.
Statewide mask mandate: persons operating in a personal capacity must wear a mask
Outside home
At businesses and in restaurants & food establishments
COVID-NET Site: Group of counties within a state. Sites in states that did not have statewide mask mandates during March 1– October 17, 2020, were excluded from the analyses.
Nonpharmaceutical Interventions (NPIs): Actions taken to slow the spread of infectious diseases.
COVID-NET: population-based surveillance system [1] that provides laboratory-confirmed, COVID-19–associated hospitalization rates in 99 counties located in 14 states, beginning March 1, 2020 [2]
For analyses, cumulative hospitalization rates for each week of the study period for seven age cohorts (adults aged 18–29, 30–39, 40–49, 50–64, 65–74, 75–84, and ≥85 years) were aggregated into three age groups (18–39, 40–64, and ≥65 years).
Weekly cumulative hospitalization growth rate (HGrowthast) for age cohort a in site s during week t is defined as the weekly percentage change in COVID-19 hospitalizations per 100,000 persons, estimated by HGrowth{ast} = ((log (HR{ast})-log (HR{as(t-1)}))×100, where HR{ast} = cumulative hospitalization rate per 100,000 population for age cohort a in site s in week t. The log of the cumulative hospitalization growth rate is similar to the log of the cumulative cases per week, as the denominators are equivalent.
For 40-64 year-olds, 2 weeks after statewide mask mandates: weekly hospitalization growth rates declined by 2.9%.
For 40-64, 18 - 39 year-olds, >= 3 weeks after statewide mask mandates: weekly hospitalization growth rates declined by 5.5%.
QUESTION: How were these age groupings made I wonder?
Zelko, Jacob. Decline in COVID-19 Hospitalization Growth Rates Associated with Statewide Mask Mandates — 10 States, March–October 2020. https://jacobzelko.com/06072021214725-decline-hospitilizations-mask. June 7 2021.
[1] “Coronavirus Disease 2019 (COVID-19)-Associated Hospitalization Surveillance Network (COVID-NET) | CDC.” https://www.cdc.gov/coronavirus/2019-ncov/covid-data/covid-net/purpose-methods.html (accessed Jun. 08, 2021).
[2] S. Garg et al., “Hospitalization rates and characteristics of patients hospitalized with laboratory-confirmed coronavirus disease 2019—COVID-NET, 14 States, March 1–30, 2020,” Morb. Mortal. Wkly. Rep., vol. 69, no. 15, p. 458, 2020.