Tenant Reports of In-Home Asthma Triggers and Adult Emergency Department Use.

Importance: Housing conditions are well recognized as a significant contributor to asthma burden. However, due to the inherent difficulty of in-home exposure assessment, there is only limited evidence evaluating the extent of population-level exposure to indoor triggers in urban environments and its link with asthma burden and disparities. Objective: To test the association between the rate of tenant reports of in-home asthma triggers and the population-based incidence rate of adult asthma emergency department (ED) visits in Boston, Massachusetts. Design, Setting, and Participants: In this cross-sectional study, tenant reports of in-home asthma triggers were obtained from Boston's housing code enforcement system. Adult asthma ED visits for Boston residents were obtained from a large health system's electronic records. Tenant reports and ED data from 2021 to 2024 and 2014 to 2018 were aggregated at the census block group level. Data from 2014 to 2018 were used as a sensitivity analysis. Main analyses were conducted January 2021 to December 2024, with a sensitivity analysis conducted January 2014 to December 2018. Exposure: Block group-level in-home asthma trigger rates across Boston were constructed using housing reporting data and demographic information from the American Community Survey. Main Outcomes and Measures: The primary outcome was the block group rate of adult asthma ED visits. Associations were tested using a bayesian generalized linear mixed model to account for spatial autocorrelation, block group demographics, household income, and traffic density. Results: In the main analysis, 2406 asthma ED visits from 1698 unique patients (median [IQR] age, 40.0 [28.0-58.0] years; 1170 female [68.9%]; 29 Asian [1.7%], 627 Black [36.9%], 271 Hispanic [16.0%], 421 White [24.8%], 621 other [36.6%]), and 7259 tenant reports linked to 552 residential block groups were analyzed. The median (IQR) rate of tenant reports at the block group level was 3.98 (1.89-6.74) per 1000 tenant-years and of adult asthma ED visits was 6.34 (2.43-16.08) per 10 000 person-years. In adjusted models, for a 1-IQR increase in the tenant report rate, there was an 8.6% (95% CI, 2.3%-16.2%) increase in the asthma ED visit rate. A sensitivity analysis of a secondary cohort including 4082 visits and 2753 patients confirmed the association between the tenant-reported asthma triggers and adult asthma ED visits, finding a 25.0% increase (95% CI, 16.9%-34.1%). Conclusions and Relevance: In this cross-sectional study, tenant-reported asthma triggers were found to be associated with adult asthma ED visits after adjusting for neighborhood-level confounders and spatial autocorrelation. These findings underscore the urgent need for policies to improve housing conditions to reduce neighborhood asthma burden.