An ecological study of COVID-19 outcomes among Florida counties

Abstract

Background: During the COVID-19 pandemic, Florida reported some of the highest number of cases and deaths in the US; however, county-level variation in COVID-19 outcomes has not been comprehensively investigated. The present ecological study aimed to assess corelates of COVID-19 outcomes among Florida counties that explain variation in case rates, mortality rates, and case fatality rates (CFR) across pandemic waves. Method: We obtained county-level administrative data and COVID-19 case reports from public repositories. We tested spatial autocorrelation to assess geographic clustering in COVID-19 outcomes: case rate, mortality rate, and CFR. Stepwise linear regression was employed to test the association between case, death, and CFR and 18 demographic, socioeconomic, and health-related county-level predictors. Results: We found mortality rate and CFR were significantly higher in rural counties compared to urban counties, among which significant differences in vaccination coverage was also observed. Multivariate analysis found that the percentage of the population aged over 65 years, the percentage of the obese people, and the percentage of rural population were significant predictors of COVID-19 case rate. Median age, vaccination coverage, percentage of people who smoke, and percentage of the population with diabetes were significant influencing factors for CFR. Importantly, vaccination coverage was significantly associated with a reduction in case rate (R = -0.26, p = 0.03) and mortality (R = -0.51, p < 0.001). Last, we found that spatial dependencies play a role in explaining variations in COVID-19 CFR among Florida counties. Conclusion: Our findings emphasize the need for targeted, equitable public health strategies to reduce disparities and enhance population resilience during public health crises. We further inform future spatial-epidemiological analyses and present actionable data for policies related to preparedness and response to current and future epidemics in Florida and elsewhere.