Dynamic associations of neighborhood social and physical environment with ED visits for asthma: A spatial change score analysis

TL;DR

This study explores how changes in neighborhood environments over time affect asthma-related emergency department visits in Los Angeles County.

Contribution

The study introduces a spatial change score analysis to assess time-varying neighborhood effects on asthma outcomes.

Findings

Increased median household income was linked to fewer asthma ED visits.

Higher PM2.5 levels were associated with more asthma ED visits.

Spatial analysis confirmed the harmful effect of PM2.5 on asthma outcomes.

Abstract

A growing number of studies identified risk factors for asthma in neighborhood social and environmental contexts. Yet, there is a lack of comprehensive knowledge about the time-varying relationship between neighborhood environmental and socioeconomic factors and asthma outcomes.

This study aimed to assess the variations in neighborhood environmental, socioeconomic, and demographic characteristics; to investigate the census tracts in Los Angeles County where emergency department (ED) visits for asthma increased; and to identify neighborhood characteristics whose change contributed to alleviating or exacerbating the burden of asthma in health care use.

Using an ecological, retrospective study design, we applied a change score method, spatial regression and geographic information system analysis to examine time-varying effects of neighborhood characteristics in Los Angeles County.

The average ED visits for asthma showed modest increases. Despite of overall improvements in neighborhood socioeconomic status, no beneficial impact of neighborhood socioeconomic status was found except median household income. Increased median household income was associated with a decrease in ED visits in socioeconomic domain. Increased particulate matter with diameter <2.5 μm (PM2.5) was associated with an increase in ED visits for asthma in environmental domain. The positive association between PM2.5 and ED visits for asthma was validated by the spatial pattern analysis.

This study identified PM2.5 as a neighborhood environmental risk factor for asthma. However, little evidence was found for the beneficial effect of improved neighborhood socioeconomic status. Our findings underscore that, in the short term, reducing traffic emissions may contribute more to lowering the burden of asthma-related health care use than improving neighborhoods’ socioeconomic status.

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