Spatial and Temporal Patterns of Chronic Disease Burden in the U.S., 2018-2021

Chronic diseases are primary causes of mortality and disability in the U.S. Although individual-level indices to assess the burden of multiple chronic diseases exist, there is a lack of quantitative tools at the population level. This gap hinders the understanding of the geographical distribution and impact of chronic diseases, crucial for effective public health strategies. This study aims to construct a Chronic Disease Burden Index (CDBI) for evaluating county-level disease burden, to identify geographic and temporal patterns, and investigate the association between CDBI and social vulnerability.

A total of 20 health measures from CDC's PLACES database (2018-2021) were used to construct annual county-level CDBIs through principal component analysis. Geographic hotspots of chronic disease burden were identified using Getis-Ord Gi*. Multinomial logistic regression models and bivariate maps were used to assess the association between CDBI and CDC's social vulnerability index. Analyses were conducted in 2023-2024.

Counties with high chronic disease burden were predominantly clustered in the southern U.S. High persistent chronic disease burden was prevalent in Kentucky and West Virginia, while increased burden was observed in Ohio and Texas. Chronic disease burden was highly associated with social vulnerability index (OR_{Q5 vs Q1}=7.6, 95% CI: [6.6, 8.8]), with nonmetro-urban counties experiencing elevated CDBI (OR=14.6, 95% CI: [9.7, 21.9]).

The CDBI offers an effective tool for assessing chronic disease burden at the population level. Identifying high-burden and vulnerable communities is a crucial first step toward facilitating resource allocation to enhance equitable healthcare access and advancing understanding of health disparities.