New Index Demonstrates Association between Social Vulnerability, Environmental Burden, and Kidney Failure Risk among Individuals with Glomerular Disease.

Abstract

BACKGROUND The Centers for Disease Control and Prevention (CDC) Environmental Justice Index Social-Environmental Ranking (EJI-SER) combines a Social Vulnerability Module (SV) with an Environmental Burden Module (EB) to characterize cumulative environmental and social burden at the census tract level. This analysis evaluates the association between EJI-SER and kidney outcomes in glomerular disease (GD) patients. METHODS Cure Glomerulopathy (CureGN) is an observational cohort study of adults and children with biopsy-proven GD. EJI-SER is a percentile ranking by census tract, with a higher score indicating a more severe burden. Associations between EJI-SER and its components with kidney failure (initiation of kidney replacement therapy, transplant, or two estimated glomerular filtration rates [eGFRs] <15ml/min/1.73m2) and longitudinal eGFR were tested using multivariable Cox regression and linear mixed models, respectively, adjusted for demographics, histologic diagnosis, eGFR and urine protein to creatinine ratio at enrollment, and time from biopsy to enrollment. RESULTS Among 1,149 participants with census tract data, the median (IQR) follow-up was 5.4 (3.0-7.0) years, the median (IQR) age at biopsy was 24 (10-48), and self-identified racial distribution was 5% Asian, 18% Black, and 70% White. Median (IQR) EJI-SER was 0.49 (0.26-0.75). EJI-SER scores in the lowest two quartiles were associated with a lower hazard of kidney failure compared to the highest quartile (adjusted HR [95% CI] 0.62 [0.36-1.08] and 0.43 [0.25-0.76] for EJI-SER 0-25% and >25-50% vs. >75%, respectively) and higher eGFR at enrolllment (adjusted mean 90.1 vs. 87.1 ml/min/1.73m2 for 0-25% vs. >75%, p=0.08). CONCLUSION As captured by EJI-SER, higher environmental and social burdens are associated with lower eGFR and a higher risk of kidney failure in the CureGN cohort. This first use of the EJI-SER in GD demonstrates the need for additional investigation into social drivers of disparities in GD and policies and resources that address these structural inequities.