Associations between state-level healthcare access and COVID-19 case trajectories in the United States

Liu, S. H.; Liu, B.; Norbury, A.; Li, Y.

Introduction: We conducted an ecological study to determine if state-level healthcare access is associated with trajectories of daily reported COVID-19 cases in the United States. Our focus is on trajectories of daily reported COVID-19 cases, rather than cumulative cases, as trajectories help us identify trends in how the pandemic naturally develops over time, and study the shapes of the curve in different states. Methods: We analyzed data on daily reported confirmed and probable COVID-19 cases from January 21 to June 16, 2020 in 50 states, adjusted for the population size of each state. Cluster analysis for time-series data was used to split the states into clusters that have distinct trajectories of daily cases. Differences in socio-demographic characteristics and healthcare access between clusters were tested. Adjusted models were used to determine if healthcare access is associated with reporting a high trajectory of COVID-19 cases. Results: Two clusters of states were identified. One cluster had a high trajectory of population-adjusted COVID-19 cases, and comprised of 19 states, including New York and New Jersey. The other cluster of states (n=31) had a low trajectory of population-adjusted COVID-19 cases. There were significantly more Black residents (p=0.027) and more nursing facility residents (p=0.001) in states reporting high trajectory of COVID-19 cases. States reporting a high trajectory of COVID-19 cases also had fewer uninsured persons (p=0.005), fewer persons who reported having to forgo medical care due to cost (p=0.016), more registered physicians (p=0.002) and more nurses (p=0.03), higher health spending per capita (p=0.01), fewer residents in Health Professional Shortage Areas per 100,000 population (p=0.027), and higher adoption of Medicaid Expansion (p=0.05). In adjusted models, a higher proportion of uninsured persons (OR: 0.51 [0.25-0.85]; p=0.032), higher proportion of patients who had to forgo medical care due to cost (OR: 0.55 [0.28-0.95]; p=0.048), and no adoption of Medicaid expansion (OR: 0.05 [0-0.59]; p=0.04), were associated with reporting a low trajectory of COVID-19 cases. Conclusion: Our findings from adjusted models suggest that healthcare access can partially explain variations in COVID-19 case trajectories by state.