Association of State Stay-at-Home Orders and State-Level African American Population with COVID-19 Case Rates

Abstract

Importance: To cope with the continuing coronavirus disease 2019 (COVID-19) pandemic, state and local officials need information on the effectiveness of policies aimed at curbing disease spread, as well as state-specific characteristics, like the racial mix, associated with increased risks related to the disease. Objective: To investigate whether state-imposed stay-at-home orders (SAHOs) and the proportion of African American population in a state were associated with the state-level COVID-19 cases. Design, Setting, and Participants: This cross-sectional study used daily, state-level data on COVID-19 cases, tests, and fatalities from the COVID Tracking Project. Data from March 1 to May 4, 2020, for all states (except Washington state) as well as the District of Columbia were used. Exposures: The key exposure variables were state-level SAHO (1 if in place, 0 otherwise), and proportion of state population who are African American. Main Outcomes and Measures: The primary outcome was daily cumulative COVID-19 case rates. A secondary outcome was subsequent COVID-19 fatality rates, derived using mean cumulative fatality rates 21 to 28 days after each date. Multivariate regression models were estimated. Results: The final sample included 3023 pooled state- and day-level observations. The mean (SD) cumulative positive case rate was 103.186 (200.067) cases per 100000 state population, the mean (SD) cumulative test rate was 744.23 (894.944) tests per 100000 state population, and the mean (SD) subsequent cumulative fatality rate was 12.923 (21.737) deaths per 100000 state population. There was a negative association of SAHOs with cumulative case rates (β = -1.166; 95% CI, -1.484 to -0.847; P