UCLA

Lung transplantation is a life-saving therapy for a carefully selected subset of patients with end-stage lung diseases. Life expectancy post-transplant is modest with a median survival of 5.5-6.5 years. The identification of potentially modifiable risk factors for poor outcomes after lung transplant is of great importance. In this dissertation, we explore the impacts of neighborhood-level social and environmental factors on lung transplant outcomes using mixed effects semiparametric and parametric survival models to estimate the hazard of death or graft failure. We find that neighborhood disinvestment, operationalized as the ZIP code level Social Vulnerability Index (SVI) is associated with a 6% increase in the hazard of death or graft failure after transplant, though this finding does not reach statistical significance. We utilize previously reported estimates of annual PM2.5 levels in North America to create ZIP code estimates of average yearly exposure. We find that annual PM2.5 exposure above the EPA standard of 12 ug/m3 is associated with an 8% increase in the hazard of death or graft failure. Furthermore, this relationship appears to hold true at lower thresholds of exposure. Understanding the effects of social and environmental factors on lung transplant outcomes will allow transplant practitioners to better identify patients at high risk of poor outcomes. It may also direct future policy decisions to mitigating these risks.