Excess Death Rates for Republican and Democratic Registered Voters in Florida and Ohio During the COVID-19 Pandemic

Abstract

Importance: There is evidence that Republican-leaning counties have had higher COVID-19 death rates than Democratic-leaning counties and similar evidence of an association between political party affiliation and attitudes regarding COVID-19 vaccination; further data on these rates may be useful.

Objective: To assess political party affiliation and mortality rates for individuals during the initial 22 months of the COVID-19 pandemic.

Design, setting, and participants: A cross-sectional comparison of excess mortality between registered Republican and Democratic voters between March 2020 and December 2021 adjusted for age and state of voter registration was conducted. Voter and mortality data from Florida and Ohio in 2017 linked to mortality records for January 1, 2018, to December 31, 2021, were used in data analysis.

Exposures: Political party affiliation.

Main outcomes and measures: Excess weekly deaths during the COVID-19 pandemic adjusted for age, county, party affiliation, and seasonality.

Results: Between January 1, 2018, and December 31, 2021, there were 538 159 individuals in Ohio and Florida who died at age 25 years or older in the study sample. The median age at death was 78 years (IQR, 71-89 years). Overall, the excess death rate for Republican voters was 2.8 percentage points, or 15%, higher than the excess death rate for Democratic voters (95% prediction interval [PI], 1.6-3.7 percentage points). After May 1, 2021, when vaccines were available to all adults, the excess death rate gap between Republican and Democratic voters widened from -0.9 percentage point (95% PI, -2.5 to 0.3 percentage points) to 7.7 percentage points (95% PI, 6.0-9.3 percentage points) in the adjusted analysis; the excess death rate among Republican voters was 43% higher than the excess death rate among Democratic voters. The gap in excess death rates between Republican and Democratic voters was larger in counties with lower vaccination rates and was primarily noted in voters residing in Ohio.

Conclusions and relevance: In this cross-sectional study, an association was observed between political party affiliation and excess deaths in Ohio and Florida after COVID-19 vaccines were available to all adults. These findings suggest that differences in vaccination attitudes and reported uptake between Republican and Democratic voters may have been factors in the severity and trajectory of the pandemic in the US.

Figure 1.. County-Level Death Counts in Florida and Ohio in Linked Voter-Mortality Data vs Centers for Disease Control and Prevention (CDC) National Center for Health Statistics Data, 2018-2021

County-level death counts for Florida and Ohio based on Datavant data that link mortality records to voter registration files against the CDC data. Each observation represents a single county. Additional details on the data are provided in the eMethods in Supplement 1.

Figure 2.. Excess Death Rates in Florida and Ohio, 2018-2021

Weekly excess deaths for Florida and Ohio based on mortality records linked to voter registration files. A, Overall excess death rates in Florida and Ohio. B, Excess death rates by registered party. C, The percentage-point difference between the registered parties, after adjusting for age and state-level differences; the smooth brown curve was fit with locally estimated scatterplot smoothing. A-C, Excess death rates were calculated for each week by comparing the observed deaths in that week with expected deaths based on a Poisson model. The 95% prediction intervals (shaded areas) were determined using simulations from the Poisson coefficient and outcome distribution, with SEs clustered at the county level. Additional details on the excess death methods and statistical analyses are presented in the eMethods in Supplement 1.

Figure 3.. Differences in Excess Death Rates for Registered Republican and Democratic Voters in Florida and Ohio During the COVID-19 Pandemic

The analyses were additionally adjusted for age and state-level differences in subgroup analyses where these covariates were not used for stratification. The 95% prediction intervals (horizontal lines) were determined using simulations from the Poisson coefficient and outcome distribution, with SEs clustered at the county level. Additional details on the excess death methodology and statistical analyses are presented in the eMethods in Supplement 1.

Figure 4.. Excess Death Rates and Vaccination Rates in Florida and Ohio During the COVID-19 Pandemic

The diamonds are binned means; counties with similar vaccination rates were binned to form 8 equally sized bins. The curves were fit to the underlying data using locally estimated scatterplot smoothing. In the pre–COVID-19 period (before April 2020), excess death rates for both Republican and Democratic voters hover around 0. During the beginning pandemic but before open vaccine eligibility (April 2020 to March 2021), the association between excess death rates and county-level vaccination rates were generally negative and nearly identical for Republican and Democratic voters. However, in the period after open vaccine eligibility (April 2021 to December 2021), there was a clear difference between Republican and Democratic voters, with higher excess death rates for Republicans concentrated in counties with lower overall vaccination rates and minimal differences in counties with the highest vaccination rates.