A 5 ug/m3 increase in PM2.5 levels following residential relocation was associated with higher odds of first hospitalization for pneumonia (OR 1.12) and COPD (OR 1.15) over 5 years.
Cohort (n=756,625)
Yes
Does an increase in PM2.5 exposure following residential relocation increase the risk of first hospitalization for pneumonia or COPD in U.S. Veterans?
Increases in PM2.5 exposure following residential relocation are associated with a significantly higher risk of hospitalization for pneumonia and COPD among U.S. Veterans.
Effect estimate: OR 1.12 (pneumonia), OR 1.15 (COPD) (95% CI 1.05-1.20 (pneumonia), 1.07-1.23 (COPD))
Abstract Rationale Air pollution, including particulate matter less than 2.5 micrometers in diameter (PM2.5), remains a significant cause of morbidity and mortality within the U.S. There have been few quasi-experimental studies that exploit residential relocation patterns to examine how individual-level changes in PM2.5 exposure are associated with subsequent respiratory health outcomes. Methods We constructed an electronic health record-based cohort of U.S. Veterans enrolled in the Veteran’s Health Administration who moved exactly once from one zip code to another between 2011 and 2017, and who had no prior hospitalizations for pneumonia or chronic obstructive pulmonary disease (COPD). Follow-up for each individual started in the year of the move and extended through 2019. We linked each Veteran to tract-level estimates of PM2.5 exposure in each year based on residential address. The exposure variable represented cumulative average annual PM2.5 level in each year following the move, minus the average PM2.5 level in the two years prior to the move. We estimated discrete time regression models to examine associations between changes in PM2.5 exposure and odds of first hospitalization for pneumonia or COPD, identified using primary ICD-9 and ICD-10 diagnostic codes. Mortality was modeled as a competing event, and models were adjusted for individual-level clinical variables, as well as area-level variables that we hypothesized could co-vary with PM2.5 and could be associated with respiratory outcomes. Pooled odds ratios (ORs) over 5 years of post-move follow-up were calculated using meta-regression. Results The analytic sample included 751,959 Veterans without a prior hospitalization for pneumonia and 756,625 Veterans without a prior hospitalization for COPD. The average difference in PM2.5 between the pre-move and post-move areas was -0.40 ug/m3, ranging from -13.2 ug/m3 to 14.3 ug/m3. In adjusted models, a 5 ug/m3 increase in PM2.5 levels between the pre-move and post-move areas was associated with a higher odds of first pneumonia hospitalization (pooled OR = 1.12, 95% CI = 1.05-1.20), and a higher odds of first COPD hospitalization (pooled OR = 1.15, 95% CI = 1.07-1.23). Conclusions In this study of U.S. Veterans, experiencing a 5 ug/m3 increase in PM2.5 levels was associated with a 12-15% increase in the odds first hospitalization for pneumonia or COPD over 5 years. Air pollution remains a substantial cause of respiratory morbidity in the U.S. Study designs using residential relocation to examine health impacts associated with intra-individual changes in PM2.5 exposure can shed light on potential health effects of air pollution reduction policies. This abstract is funded by: National Heart, Lung, and Blood Institute, National Institutes of Health
Titus et al. (Fri,) conducted a cohort in Pneumonia and Chronic Obstructive Pulmonary Disease (COPD) (n=756,625). Change in PM2.5 exposure vs. Pre-move PM2.5 levels was evaluated on First hospitalization for pneumonia or COPD (OR 1.12 (pneumonia), OR 1.15 (COPD), 95% CI 1.05-1.20 (pneumonia), 1.07-1.23 (COPD)). A 5 ug/m3 increase in PM2.5 levels following residential relocation was associated with higher odds of first hospitalization for pneumonia (OR 1.12) and COPD (OR 1.15) over 5 years.