Association of State-Issued Mask Mandates and Allowing On-Premises Restaurant Dining with County-Level COVID-19 Case and Death Growth Rates — United States, March 1–December 31, 2020

CDC recommends a combination of evidence-based
strategies to reduce transmission of SARS-CoV-2, the virus
that causes COVID-19 (1). Because the virus is transmitted
predominantly by inhaling respiratory droplets from infected
persons, universal mask use can help reduce transmission (1).
Starting in April, 39 states and the District of Columbia (DC)
issued mask mandates in 2020. Reducing person-to-person
interactions by avoiding nonessential shared spaces, such as
restaurants, where interactions are typically unmasked and
physical distancing (≥6 ft) is difficult to maintain, can also
decrease transmission (2). In March and April 2020, 49 states
and DC prohibited any on-premises dining at restaurants, but
by mid-June, all states and DC had lifted these restrictions.
To examine the association of state-issued mask mandates and
allowing on-premises restaurant dining with COVID-19 cases
and deaths during March 1–December 31, 2020, countylevel data on mask mandates and restaurant reopenings were
compared with county-level changes in COVID-19 case and
death growth rates relative to the mandate implementation and
reopening dates.

Mask mandates were associated with decreases
in daily COVID-19 case and death growth rates 1–20, 21–40,
41–60, 61–80, and 81–100 days after implementation.
Allowing any on-premises dining at restaurants was associated
with increases in daily COVID-19 case growth rates 41–60,
61–80, and 81–100 days after reopening, and increases in
daily COVID-19 death growth rates 61–80 and 81–100 days
after reopening. Implementing mask mandates was associated
with reduced SARS-CoV-2 transmission, whereas reopening restaurants for on-premises dining was associated with
increased transmission. Policies that require universal mask use
and restrict any on-premises restaurant dining are important

components of a comprehensive strategy to reduce exposure to
and transmission of SARS-CoV-2 (1). Such efforts are increasingly important given the emergence of highly transmissible
SARS-CoV-2 variants in the United States (3,4).
County-level data on state-issued mask mandates and restaurant
closures were obtained from executive and administrative orders
identified on state government websites. Orders were analyzed
and coded to extract mitigation policy variables for mask mandates and restaurant closures, their effective dates and expiration
dates, and the counties to which they applied. State-issued mask
mandates were defined as requirements for persons to wear a
mask 1) anywhere outside their home or 2) in retail businesses
and in restaurants or food establishments. State-issued restaurant
closures were defined as prohibitions on restaurants operating or
limiting service to takeout, curbside pickup, or delivery. Allowing
restaurants to provide indoor or outdoor on-premises dining was
defined as the state lifting a state-issued restaurant closure.* All
coding underwent secondary review and quality assurance checks
by two or more raters; upon agreement among all raters, coding
and analyses were published in freely available data sets.†,§
Two outcomes were examined: the daily percentage point
growth rate of county-level COVID-19 cases and countylevel COVID-19 deaths. The daily growth rate was defined
as the difference between the natural log of cumulative cases

or deaths on a given day and the natural log of cumulative
cases or deaths on the previous day, multiplied by 100. Data
on cumulative county-level COVID-19 cases and deaths were
collected from state and local health department websites and
accessed through U.S. Department of Health and Human
Services Protect.

Associations between the policies and COVID-19 outcomes
were measured using a reference period (1–20 days before
implementation) compared with seven mutually exclusive
time ranges relative to implementation (i.e., the effective date
of the mask mandate or the date restaurants were permitted
to allow on-premises dining). The association was examined
over two preimplementation periods (60–41 and 40–21 days
before implementation) and five postimplementation periods (1–20, 21–40, 41–60, 61–80, and 81–100 days after
implementation).

Weighted least-squares regression with county and day fixed
effects was used to compare COVID-19 case and death growth
rates before and after 1) implementing mask mandates and 2)
allowing on-premises dining at restaurants. Because state-issued
policies often applied to specific counties, particularly when
states began allowing on-premises dining, all analyses were
conducted at the county level. Four regression models were
used to assess the association between each policy and each
COVID-19 outcome. The regression models controlled for several covariates: restaurant closures in the mask mandate models
and mask mandates in the restaurant reopening models, as well
as bar closures,** stay-at-home orders,†† bans on gatherings

of ≥10 persons,§§ daily COVID-19 tests per 100,000 persons, county, and time (day). P-values <0.05 were considered
statistically significant. All analyses were weighted by county
population with standard errors robust to heteroscedasticity
and clustered by state. Analyses were performed using Stata
software (version 14.2; StataCorp). This activity was reviewed
by CDC and was conducted consistent with applicable federal
law and CDC policy.

During March 1–December 31, 2020, state-issued mask
mandates applied in 2,313 (73.6%) of the 3,142 U.S. counties. Mask mandates were associated with a 0.5 percentage
point decrease (p = 0.02) in daily COVID-19 case growth
rates 1–20 days after implementation and decreases of 1.1,
1.5, 1.7, and 1.8 percentage points 21–40, 41–60, 61–80, and
81–100 days, respectively, after implementation (p<0.01 for all)
(Table 1) (Figure). Mask mandates were associated with a 0.7
percentage point decrease (p = 0.03) in daily COVID-19 death
growth rates 1–20 days after implementation and decreases of
1.0, 1.4, 1.6, and 1.9 percentage points 21–40, 41–60, 61–80,
and 81–100 days, respectively, after implementation (p<0.01
for all). Daily case and death growth rates before implementation of mask mandates were not statistically different from the
reference period.

During the study period, states allowed restaurants to reopen
for on-premises dining in 3,076 (97.9%) U.S. counties.
Changes in daily COVID-19 case and death growth rates were
not statistically significant 1–20 and 21–40 days after restrictions were lifted. Allowing on-premises dining at restaurants
was associated with 0.9 (p = 0.02), 1.2 (p<0.01), and 1.1

 

 

FIGURE. Association between changes in COVID-19 case and death growth rates* and implementation of state mask mandates† (A) and states
allowing any on-premises restaurant dining§ (B) — United States, March 1–December 31, 2020

* With 95% confidence intervals indicated with error bars.
† A state-issued mask mandate was defined as the requirement that persons operating in a personal capacity (i.e., not limited to specific professions or employees)
wear a mask 1) anywhere outside their home or 2) in retail businesses and in restaurants or food establishments.
§ The effective date of the state order allowing restaurants to conduct any on-premises dining or the date a state-issued restaurant closure expired

(p = 0.04) percentage point increases in the case growth rate
41–60, 61–80, and 81–100 days, respectively, after restrictions
were lifted (Table 2) (Figure). Allowing on-premises dining at
restaurants was associated with 2.2 and 3.0 percentage point
increases in the death growth rate 61–80 and 81–100 days,
respectively, after restrictions were lifted (p<0.01 for both).
Daily death growth rates before restrictions were lifted were not
statistically different from those during the reference period,
whereas significant differences in daily case growth rates were
observed 41–60 days before restrictions were lifted.

Discussion
Mask mandates were associated with statistically significant
decreases in county-level daily COVID-19 case and death growth
rates within 20 days of implementation. Allowing on-premises

restaurant dining was associated with increases in county-level
case and death growth rates within 41–80 days after reopening. State mask mandates and prohibiting on-premises dining
at restaurants help limit potential exposure to SARS-CoV-2,
reducing community transmission of COVID-19.
Studies have confirmed the effectiveness of community mitigation measures in reducing the prevalence of
COVID-19 (5–8). Mask mandates are associated with reductions in COVID-19 case and hospitalization growth rates (6,7),
whereas reopening on-premises dining at restaurants, a known
risk factor associated with SARS-CoV-2 infection (2), is associated with increased COVID-19 cases and deaths, particularly
in the absence of mask mandates (8). The current study builds
upon this evidence by accounting for county-level variation in state-issued mitigation measures and highlights the importance of a comprehensive strategy to decrease exposure to and transmission of SARS-CoV-2.

Prohibiting on-premises
restaurant dining might assist in limiting potential exposure
to SARS-CoV-2; however, such orders might disrupt daily life
and have an adverse impact on the economy and the food services industry (9). If on-premises restaurant dining options are
not prohibited, CDC offers considerations for operators and
customers which can reduce the risk of spreading COVID-19
in restaurant settings.*** COVID-19 case and death growth
rates might also have increased because of persons engaging in
close contact activities other than or in addition to on-premises
restaurant dining in response to perceived reduced risk as a
result of states allowing restaurants to reopen. Further studies
are needed to assess the effect of a multicomponent community
mitigation strategy on economic activity.
Increases in COVID-19 case and death growth rates were
significantly associated with on-premises dining at restaurants
after indoor or outdoor on-premises dining was allowed by the
state for >40 days. Several factors might explain this observation. Even though prohibition of on-premises restaurant
dining was lifted, restaurants were not required to open and
might have delayed reopening. In addition, potential restaurant patrons might have been more cautious when restaurants
initially reopened for on-premises dining but might have been
more likely to dine at restaurants as time passed. Further
analyses are necessary to evaluate the delayed increase in case
and death growth rates.
The findings in this report are subject to at least three limitations. First, although models controlled for mask mandates,
restaurant and bar closures, stay-at-home orders, and gathering
bans, the models did not control for other policies that might

affect case and death rates, including other types of business
closures, physical distancing recommendations, policies issued
by localities, and variances granted by states to certain counties
if variances were not made publicly available. Second, compliance with and enforcement of policies were not measured.
Finally, the analysis did not differentiate between indoor and
outdoor dining, adequacy of ventilation, and adherence to
physical distancing and occupancy requirements.
Community mitigation measures can help reduce the
transmission of SARS-CoV-2. In this study, mask mandates
were associated with reductions in COVID-19 case and death
growth rates within 20 days, whereas allowing on-premises dining at restaurants was associated with increases in COVID-19
case and death growth rates after 40 days. With the emergence
of more transmissible COVID-19 variants, community mitigation measures are increasingly important as part of a larger
strategy to decrease exposure to and reduce transmission of
SARS-CoV-2 (3,4). Community mitigation policies, such as
state-issued mask mandates and prohibition of on-premises
restaurant dining, have the potential to slow the spread of
COVID-19, especially if implemented with other public health
strategies (1,10).

Acknowledgments
Angela Werner; Timmy Pierce; Nicholas Skaff; Matthew Penn.
CDC COVID-19 Response Team, Mitigation Policy Analysis Unit
Moriah Bailey, CDC; Amanda Brown, CDC; Ryan Cramer,
CDC; Catherine Clodfelter, CDC; Robin Davison, CDC; Sebnem
Dugmeoglu, CDC; Arriana Fitts, CDC; Siobhan Gilchrist, CDC;
Rachel Hulkower, CDC; Alexa Limeres, CDC; Dawn Pepin, CDC;
Adebola Popoola, CDC; Morgan Schroeder, CDC; Michael A.
Tynan, CDC; Chelsea Ukoha, CDC; Michael Williams, CDC;
Christopher D. Whitson, CDC.

CDC Public Health Law Program
Gi Jeong, CDC; Lisa Landsman, CDC; Amanda Moreland, CDC;
Julia Shelburne, CDC.
Corresponding author: Gery P. Guy Jr., irm2@cdc.gov.
1CDC COVID-19 Response Team; 2CDC Public Health Law Program;
3University of Nevada, Las Vegas.
All authors have completed and submitted the International
Committee of Medical Journal Editors form for disclosure of potential
conflicts of interest. No potential conflicts of interest were disclosed.

References
1. Honein MA, Christie A, Rose DA, et al.; CDC COVID-19 Response
Team. Summary of guidance for public health strategies to address high
levels of community transmission of SARS-CoV-2 and related deaths,
December 2020. MMWR Morb Mortal Wkly Rep 2020;69:1860–7.
PMID:33301434 https://doi.org/10.15585/mmwr.mm6949e2

2. Fisher KA, Tenforde MW, Feldstein LR, et al.; IVY Network Investigators;
CDC COVID-19 Response Team. Community and close contact
exposures associated with COVID-19 among symptomatic adults
≥18 years in 11 outpatient health care facilities—United States, July 2020.
MMWR Morb Mortal Wkly Rep 2020;69:1258–64. PMID:32915165
https://doi.org/10.15585/mmwr.mm6936a5
3. Galloway SE, Paul P, MacCannell DR, et al. Emergence of SARS-CoV-2
B.1.1.7 lineage—United States, December 29, 2020–January 12, 2021.
MMWR Morb Mortal Wkly Rep 2021;70:95–9. PMID:33476315
https://doi.org/10.15585/mmwr.mm7003e2
4. CDC. COVID-19: variants of the virus that causes COVID-19. Atlanta,
GA: US Department of Health and Human Services, CDC; 2021. https://
http://www.cdc.gov/coronavirus/2019-ncov/variants/index.html
5. Courtemanche C, Garuccio J, Le A, Pinkston J, Yelowitz A. Strong social
distancing measures in the United States reduced the COVID-19 growth
rate. Health Aff (Millwood) 2020;39:1237–46. PMID:32407171 https://
doi.org/10.1377/hlthaff.2020.00608
6. Lyu W, Wehby GL. Community use of face masks and COVID-19:
evidence from a natural experiment of state mandates in the US. Health
Aff (Millwood) 2020;39:1419–25. PMID:32543923 https://doi.
org/10.1377/hlthaff.2020.00818

7. Joo H, Miller GF, Sunshine G, et al. Decline in COVID-19 hospitalization
growth rates associated with statewide mask mandates—10 states,
March–October 2020. MMWR Morb Mortal Wkly Rep 2021;70:212–6.
PMID:33571176 https://doi.org/10.15585/mmwr.mm7006e2
8. Kaufman BG, Whitaker R, Mahendraratnam N, Smith VA, McClellan
MB. Comparing associations of state reopening strategies with
COVID-19 burden. J Gen Intern Med 2020;35:3627–34.
PMID:33021717 https://doi.org/10.1007/s11606-020-06277-0
9. Nicola M, Alsafi Z, Sohrabi C, et al. The socio-economic implications
of the coronavirus pandemic (COVID-19): a review. Int J Surg
2020;78:185–93. PMID:32305533 https://doi.org/10.1016/j.
ijsu.2020.04.018
10. Fuller JA, Hakim A, Victory KR, et al.; CDC COVID-19 Response
Team. Mitigation policies and COVID-19–associated
mortality—37 European countries, January 23–June 30, 2020. MMWR
Morb Mortal Wkly Rep 2021;70:58–62. PMID:33443494 https://doi.
org/10.15585/mmwr.mm7002e4

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