Rurality and neighborhood socioeconomic status are associated with overall and cause-specific mortality and hepatic decompensation in type 2 diabetes.

Abstract

Introduction: Social determinants of health are key factors driving disease progression. In type 2 diabetes there is limited literature on how distal or intermediate factors (e.g., those at the neighborhood level) influence cause-specific mortality or liver disease outcomes.

Methods: This was a single-center retrospective study of patients with type 2 diabetes seen at an integrated healthcare system in the United States. The primary outcomes were overall mortality; death due to cardiovascular disease, cancer, or liver disease; or hepatic decompensation. The primary predictors were neighborhood-level (intermediate) factors measuring neighborhood poverty (Area Deprivation Index [ADI], affluence score, disadvantage score) and rurality (Rural-Urban Commuting Area scores). Associations were modeled using Cox proportional hazards or Fine-Grey competing risk models.

Results: 28,424 participants were included. Higher neighborhood poverty associated with increased overall mortality, with hazard ratio (HR) 1.11 (95% confidence interval 1.10-1.12, p<0.001) per 10 points of ADI and HR 1.32 (95% CI 1.26-1.37, p<0.001) for 10 points of disadvantage. Conversely, higher neighborhood affluence associated with lower overall mortality with HR 0.87 (95% CI 0.86-0.89, p<0.001) per 10 points of affluence. Living in a rural region associated with increased overall mortality: HR 1.08 (95% CI 1.01-1.15, p=0.031). Associations were consistent across cause-specific mortality, though effect sizes were larger for liver-related mortality than for other causes. Living in a more rural neighborhood was associated with increased risk of hepatic decompensation.

Conclusions: Intermediate neighborhood-level socioeconomic status was associated with overall and cause-specific mortality in type 2 diabetes, with larger effects on liver-related mortality than other causes.