CF Lung Transplant Survival by Surrogate Markers for Socioeconomic Status

Abstract

Studies have shown that markers of socioeconomic status (SES) such as education level and non-private insurance status associate with decreased medical adherence in patients with Cystic Fibrosis (CF), as well as increased CF mortality. Further, patients with lower SES are less likely to be referred for lung transplantation (Ltx) by their longitudinal providers. However, little is known about whether the presence of such factors is indeed associated with worse outcomes after Ltx. This study aims to evaluate the hypothesis that education and insurance status are associated with CF-patient survival following Ltx. We retrospectively reviewed the Scientific Registry of Transplant Recipients (SRTR) database for 2,697 adult CF LTx patients from 2005 through 2019. Patients were stratified by insurance status (private, Medicaid, Medicare, and other- including VA/CHIP), and educational attainment (grade school, high school, any college). All-cause mortality was examined with Cox proportional hazard regression (adjusted for age, sex, disease severity, center volume, and CMV mismatch), and the Kaplan-Meier method was used to model survival. Of 2,697 CF LTx recipients, 1,522 (56.4%) had private insurance; 410 (15.2%) had Medicaid; 666 (24.7%) had Medicare; and 97(3.6%) had other types. 20 (0.7%) patients had less than a high school education, 839 (31.1%) completed only high school, and 1,701 (63.1%) had any college or above. During the study period, there were 942 patient deaths (34.9%). Educational attainment of high school (or less) and non-private insurance status were strongly associated with lower survival rates at 2-years, 5 years, and 10 years. In multivariate analyses, non-private insurance and non-post-secondary education increased the risk of death with a hazard ratio 1.33 (95% CI 1.11 to 1.60, p=0.002) and 1.31(95% CI 1.08 to 1.59, p=0.006) respectively. This study represents the largest cohort with longest follow-up evaluating the effect of two separate SES surrogates on survival in CF LTx recipients. Improved survival associated with private insurance and post-secondary education. Further investigation must be taken to understand the nuanced social determinants of health affecting this observation.