Population-Based Impact of Rurality and Neighborhood-Level Socioeconomic Disadvantage on Pediatric Cancer Mortality in Washington State

Background: Childhood cancer-related mortality differs by socioeconomic factors, but the impact of residential location, including rurality and neighborhood-level socioeconomic disad-vantage, is not well-characterized.Methods: This retrospective cohort study linked Washington State cancer registry data (1992-2013) to state birth (1974-2013) and death records (1992-2013) to identify residents <20 years diagnosed with cancer (n = 4,306). Census-based rural-urban commuting area codes and Area Deprivation Index (ADI) defined rural residence and neighborhood socioeconomic disadvantage at time of cancer diag-nosis, respectively. Neighborhoods in the highest state ADI quintile were classified as the most disadvantaged. Kaplan-Meier estimates and Cox hazards models, adjusted for key characteristics, were used to compare mortality by rural and ADI classification.Results: Five-year overall survival for children from non rural low ADI neighborhoods (referent) was 80.9%+/- 0.8%, versus 66.4%+/- 2.9% from non-rural high ADI neighborhoods, 69.4%+/- 3.8% from rural low ADI neighborhoods, and 66.9%+/- 3.8% from rural high ADI neighborhoods (P < 0.01 for each compar-ison versus referent). Compared with the referent group, children from comparator neighborhoods had a greater mortality risk: Rural low ADI [hazard ratio (HR), 1.50; 95% confidence interval (CI), 1.12-2.02], rural high ADI (HR, 1.53; 95% CI, 1.16-2.01), and non-rural high ADI (HR, 1.64; 95% CI, 1.32-2.04). Associa-tions of ADI and rurality with mortality varied in sub-analyses by cancer type.Conclusions: Children with cancer living in rural and/or socio-economically disadvantaged neighborhoods at diagnosis experi-enced greater mortality relative to those without either factor. Impact: Future investigation is needed to examine how rurality and poverty potentially impact healthcare utilization and health -related outcomes in pediatric oncology.