Income and rural–urban status moderate the association between income inequality and life expectancy in US census tracts

Abstract Background A preponderance of evidence suggests that higher income inequality is associated with poorer population health, yet recent research suggests that this association may vary based on other social determinants, such as socioeconomic status (SES) and other geographic factors, such as...

Full description

Bibliographic Details
Main Authors: Steven A. Cohen, Caitlin C. Nash, Erin N. Byrne, Mary L. Greaney
Format: Article
Language:English
Published: BMC 2023-03-01
Series:Journal of Health, Population and Nutrition
Subjects:
Online Access:https://doi.org/10.1186/s41043-023-00366-6
_version_ 1797853735894908928
author Steven A. Cohen
Caitlin C. Nash
Erin N. Byrne
Mary L. Greaney
author_facet Steven A. Cohen
Caitlin C. Nash
Erin N. Byrne
Mary L. Greaney
author_sort Steven A. Cohen
collection DOAJ
description Abstract Background A preponderance of evidence suggests that higher income inequality is associated with poorer population health, yet recent research suggests that this association may vary based on other social determinants, such as socioeconomic status (SES) and other geographic factors, such as rural–urban status. The objective of this empirical study was to assess the potential for SES and rural–urban status to moderate the association between income inequality and life expectancy (LE) at the census-tract level. Methods Census-tract LE values for 2010–2015 were abstracted from the US Small-area Life Expectancy Estimates Project and linked by census tract to Gini index, a summary measure of income inequality, median household income, and population density for all US census tracts with non-zero populations (n = 66,857). Partial correlation and multivariable linear regression modeling was used to examine the association between Gini index and LE using stratification by median household income and interaction terms to assess statistical significance. Results In the four lowest quintiles of income in the four most rural quintiles of census tracts, the associations between LE and Gini index were significant and negative (p between < 0.001 and 0.021). In contrast, the associations between LE and Gini index were significant and positive for the census tracts in the highest income quintiles, regardless of rural–urban status. Conclusion The magnitude and direction of the association between income inequality and population health depend upon area-level income and, to a lesser extent, on rural–urban status. The rationale behind these unexpected findings remains unclear. Further research is needed to understand the mechanisms driving these patterns.
first_indexed 2024-04-09T19:55:31Z
format Article
id doaj.art-a4f16ffad842458b8d70f5f7888f6828
institution Directory Open Access Journal
issn 2072-1315
language English
last_indexed 2024-04-09T19:55:31Z
publishDate 2023-03-01
publisher BMC
record_format Article
series Journal of Health, Population and Nutrition
spelling doaj.art-a4f16ffad842458b8d70f5f7888f68282023-04-03T05:31:11ZengBMCJournal of Health, Population and Nutrition2072-13152023-03-014211810.1186/s41043-023-00366-6Income and rural–urban status moderate the association between income inequality and life expectancy in US census tractsSteven A. Cohen0Caitlin C. Nash1Erin N. Byrne2Mary L. Greaney3Department of Health Studies, College of Health Sciences, University of Rhode IslandDepartment of Health Studies, College of Health Sciences, University of Rhode IslandDepartment of Health Studies, College of Health Sciences, University of Rhode IslandDepartment of Health Studies, College of Health Sciences, University of Rhode IslandAbstract Background A preponderance of evidence suggests that higher income inequality is associated with poorer population health, yet recent research suggests that this association may vary based on other social determinants, such as socioeconomic status (SES) and other geographic factors, such as rural–urban status. The objective of this empirical study was to assess the potential for SES and rural–urban status to moderate the association between income inequality and life expectancy (LE) at the census-tract level. Methods Census-tract LE values for 2010–2015 were abstracted from the US Small-area Life Expectancy Estimates Project and linked by census tract to Gini index, a summary measure of income inequality, median household income, and population density for all US census tracts with non-zero populations (n = 66,857). Partial correlation and multivariable linear regression modeling was used to examine the association between Gini index and LE using stratification by median household income and interaction terms to assess statistical significance. Results In the four lowest quintiles of income in the four most rural quintiles of census tracts, the associations between LE and Gini index were significant and negative (p between < 0.001 and 0.021). In contrast, the associations between LE and Gini index were significant and positive for the census tracts in the highest income quintiles, regardless of rural–urban status. Conclusion The magnitude and direction of the association between income inequality and population health depend upon area-level income and, to a lesser extent, on rural–urban status. The rationale behind these unexpected findings remains unclear. Further research is needed to understand the mechanisms driving these patterns.https://doi.org/10.1186/s41043-023-00366-6Socioeconomic statusIncome inequalityPopulation healthGeography
spellingShingle Steven A. Cohen
Caitlin C. Nash
Erin N. Byrne
Mary L. Greaney
Income and rural–urban status moderate the association between income inequality and life expectancy in US census tracts
Journal of Health, Population and Nutrition
Socioeconomic status
Income inequality
Population health
Geography
title Income and rural–urban status moderate the association between income inequality and life expectancy in US census tracts
title_full Income and rural–urban status moderate the association between income inequality and life expectancy in US census tracts
title_fullStr Income and rural–urban status moderate the association between income inequality and life expectancy in US census tracts
title_full_unstemmed Income and rural–urban status moderate the association between income inequality and life expectancy in US census tracts
title_short Income and rural–urban status moderate the association between income inequality and life expectancy in US census tracts
title_sort income and rural urban status moderate the association between income inequality and life expectancy in us census tracts
topic Socioeconomic status
Income inequality
Population health
Geography
url https://doi.org/10.1186/s41043-023-00366-6
work_keys_str_mv AT stevenacohen incomeandruralurbanstatusmoderatetheassociationbetweenincomeinequalityandlifeexpectancyinuscensustracts
AT caitlincnash incomeandruralurbanstatusmoderatetheassociationbetweenincomeinequalityandlifeexpectancyinuscensustracts
AT erinnbyrne incomeandruralurbanstatusmoderatetheassociationbetweenincomeinequalityandlifeexpectancyinuscensustracts
AT marylgreaney incomeandruralurbanstatusmoderatetheassociationbetweenincomeinequalityandlifeexpectancyinuscensustracts