Introduction: No studies have examined whether social determinants of health (SDOH) have a synergistic effect on health outcomes. The study aim is to examine the synergistic impact of socioeconomic status (SES), psychosocial and neighborhood factors on mortality in U.S. adults with diabetes and CKD.
Methods: We analyzed data from NHANES (2005-2010) for adults linked to mortality follow-up. Primary outcome was all-cause mortality. CKD stage was based on eGFR and albumin-to-creatinine ratio. Diabetes was based on self-report or HbA1c ≥6.5%. Cox proportional hazards models was used to estimate the association between SES (poverty income ratio(PIR)), psychosocial (depression) and neighborhood factors (food insecurity-FI) on all-cause mortality as independent predictors and in a joint-effect model while controlling for covariates.
Results: This study included 994 adults (representing 8,188,150 U.S. adults) with diabetes. The sample mean age was 66 years, 40% Non-Hispanic white, 27% Non-Hispanic black, 68% had a ≤high school degree, 39% had PIR of ≤130%, 49% with CKD stage 1-2 and 51% with CKD stage 3-5. In individuals with diabetes and CKD, an increase in PIR was associated with 19% lower mortality (unadjusted HR=0.81, 95% CI=0.68-0.96) while food insecurity (unadjusted HR=0.92, 95% CI=0.72-1.18) and depression (unadjusted HR=1.03, 95% CI=0.98-1.08) did not have a significant effect. After adjusting for demographics, lifestyle, access to care, risk factor control and comorbidities, FI was associated with a 29% higher mortality (adjusted HR=1.29, 95% CI=1.04-1.60); PIR was associated with 22% lower mortality (adjusted HR=0.78, 95% CI=0.61-1.01), marginally significant and depression remained non-significant (adjusted HR=1.02, 95% CI=0.98-1.07). SDOH factors such as FI are an important determinant of mortality risk in this population independent of other SDOH such as SES, psychosocial factor etc. and non-SDOH factors such as lifestyle, access to care, diabetes control etc.
M.N. Ozieh: None. E. Garacci: None. L.E. Egede: Consultant; Self; Novo Nordisk Inc. Research Support; Self; National Institute of Diabetes and Digestive and Kidney Diseases.