Identifying disparities in air pollution-attributable cardiovascular health outcomes within a quasi-experimental framework

PROJECT SUMMARY/ABSTRACT Air pollution – including exposure to particulate matter (PM) – is a leading cause of morbidity and mortality in the United States and worldwide. However, existing research examining the cardiovascular health effects of PM2.5 exposure has several limitations, including residual confounding by correlated spatial and temporal characteristics, and limited or conflicting evidence regarding the extent to which associations between PM2.5 and health outcomes vary according to individual and neighborhood characteristics. Moreover, few national studies in the U.S. on the cardiovascular effects of PM2.5 have encapsulated a spectrum of health outcomes, ranging from changes in systolic blood pressure (SBP) to hospitalizations and mortality. Examining associations between air pollution and a continuum of cardiovascular disease (CVD) outcomes contributes to our understanding of causal mechanisms and sheds light on potential intervention opportunities. The goal of this K01 award is to address gaps in the literature while also supporting the candidate’s goal of transitioning to an independent scholar focused on identifying and addressing upstream environmental determinants of CVD disparities. Through formal coursework, workshops, mentored research, and attendance at scientific conferences, Dr. Titus will gain expertise in the pathogenesis of pollution-attributable CVD outcomes, and will pursue methodological training in causal inference, multi-level EHR-based analyses, and machine learning approaches. Building on Dr. Titus’s prior training as a social epidemiologist, these complementary training and research aims will allow Dr. Titus to elucidate complex, intersectional patterns of vulnerability to the health effects of air pollution and will provide her with a combination of methodological tools that can be flexibly applied to future research questions at the nexus of environmental health, cardiovascular epidemiology, and health disparities. The proposed research will leverage EHR data from a large, national cohort of U.S. veterans to examine associations between long-term PM2.5 exposure and CVD disparities within a novel quasi-experimental framework, exploiting individual-level changes in PM2.5 exposure based on residential mobility. The proposed aims 1) examine associations between PM2.5 and CVD-related outcomes (changes in SBP, hospitalizations and mortality) among all veterans, 2) use hypothesis-driven approaches to examine how associations vary according to socioeconomic status and urbanicity, and 3) use machine learning methods to explore intersectional patterns of PM2.5-attributable CVD outcomes based on individual and area-level characteristics. This work is in line with NHLBI’s strategic goals to elucidate drivers of population disparities in CVD and to pursue novel linkages of large-scale environmental and EHR data. By providing salary support, training, and a formal mentorship structure, this award will facilitate Dr. Titus’s transition to an independent career focused on the study of environmentally driven CVD disparities.