Residential Land Use Regulation and Chronic Disease Disparities by Income Level

Background: Residential land use regulation refers to local government regulations that restrict how land is developed. They are the most important factor in the restriction of housing supply and is directly related to the unaffordability of housing in many cities.
Methods: The purpose of this ecologic study is to investigate the relationship between residential land use regulation and health disparities by income level. An index measuring the level of land use regulation in Metropolitan Statistical Areas (MSAs) was merged with survey data on prevalence of cardiovascular disease, diabetes, and asthma that were used to calculate a health disparities index. A linear regression model was fit to test for an association between baseline level of regulation in 2006 and change in chronic disease disparities by income in MSAs across the U.S. from 2006 to 2018. A first-differences model was fit to analyze the association between the change in level of land use regulation and change in chronic disease disparities by income in MSAs across the U.S. from 2006 to 2018.
Results: MSAs with more restrictive land use regulation in 2006 tend to be from west and northeast regions of the US and have a larger population compared to the MSAs with lower levels of regulation. The results from the regression models suggest a weak positive relationship between the restrictiveness of land use regulation and health disparities by income. After adjusting for population size, median age, and region, each one-unit difference in WRLURI at baseline was associated with an increase in HDI from 2006 to 2018 of 0.17 (95% CI: -0.25, 0.59). The results from the Model 2 suggest that a one-unit change in the level of regulation from 2006 to 2018 is associated with a 0.08 (95% CI: -0.26, 0.42) increase in HDI on average. However, the results of both models were not statistically significant.
Discussion: In conclusion, there is a suggestive positive relationship between the level of residential land use regulation in US metropolitan areas and the relative difference in risk of chronic disease between those with higher incomes compared to those with lower incomes; however, the role of chance cannot be ruled out. Study power was a limitation given small number of MSAs. More research is needed to learn about the mechanisms in which residential
land use regulation might impact health.