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 disadvantage, 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 diagnosis, 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 comparison 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). Associations of ADI and rurality with mortality varied in sub-analyses by cancer type.

Conclusions: Children with cancer living in rural and/or socioeconomically disadvantaged neighborhoods at diagnosis experienced 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.