Comparing Neighborhood Indices of Socioeconomic Status, Segregation, and Healthcare Access for Predicting Late-Stage Breast Cancer.

Composite indices of neighborhood-level social environment are frequently used in cancer research, but relationships among these indices have been seldom studied, especially in race-stratified analyses. We considered four census tract-level social indices: Neighborhood Deprivation Index (NDI; continuous, quartiles, and clusters); Yost (continuous, quartiles, and clusters); racialized-income Index of Concentration at the Extremes (ICE; continuous, quartiles, and clusters); and a care access metric (categorical). These were linked to the Carolina Breast Cancer Study, a cohort of 2998 adults (50% Black, 50% aged < 50 years) with invasive breast cancer, diagnosed 2008-2013 in North Carolina, USA. Age-adjusted associations of each index with late-stage breast cancer (stage III-IV) were assessed using generalized linear models and relative frequency differences (RFDs) and 95% confidence intervals (CIs). There were strong correlations (> 0.79 for pairwise comparisons) between the continuous NDI, Yost, and ICE, but pairwise agreement was moderate (55% to 70%) among indices as quartiles. Care access had low concordance with the other three indices. Among Black participants, late-stage breast cancer was associated with all indices, including the most disadvantaged quartile (vs least) of NDI (RFD = 7.0%, 95% CI: 1.6, 12.4), Yost (RFD = 8.8%, 95% CI: 3.3, 14.3), and ICE (RFD = 7.6%, 95% CI: 2.2, 13.0) and was strongly associated with care access (RFD = 9.4%, 95% CI: 3.8, 15.0). These associations were not significant among non-Black participants. Overall, multiple neighborhood-level social indices, including one based on healthcare data, are associated with late-stage breast cancer among Black participants, suggesting multiple dimensions of vulnerability to structural barriers.