Evaluating the impact of keeping indoor dining closed on COVID-19 rates among large US cities: a quasi-experimental design

Objective: Indoor dining is one of the potential key drivers of COVID-19 transmission. We leverage the heterogeneity in state government preemption of city indoor dining closures, to estimate the impact of keeping indoor dining closed on COVID-19 incidence. Methods: We obtained case rates and city/state re-opening dates from March to October 2020 in 11 U.S. cities. We categorized cities as (treatment) cities that were allowed by the state to reopen but kept indoor dining closed; and (comparison) cities that would have kept indoor dining closed but were preempted by their state and had to reopen indoor dining. Results: Keeping indoor dining closed was associated with a 43% (IRR=0.57, 95% CI 0.46 to 0.69) decline in COVID-19 incidence over 4-weeks compared with cities that reopened indoor dining. These results were consistent after testing alternative modeling strategies. Conclusions: Keeping indoor dining closed contributes to reductions in COVID-19 spread. Policy Implications: Evidence of the relationship between indoor dining and COVID-19 incidence can inform state and local decisions to restrict indoor dining as a tailored strategy to reduce COVID-19 incidence.