Relationships Between Census Tract-Level Social Determinants of Health and Cardiovascular Care Among Individuals Diagnosed With Breast Cancer

OBJECTIVES: Individuals diagnosed with breast cancer (BC) who have undergone cardio-toxic treatments (i.e., radiation therapy, anthracyclines, or HER2-targeted therapy) should visit a cardiologist. Cardiovascular care is impacted by social determinants of health (SDOH), however this relationship is poorly understood in the BC patient population setting. We investigate the relationship among individuals diagnosed with BC who started cardio-toxic treatment and SDOH.

METHODS: This study used Surveillance, Epidemiology, and End Results-Medicare data linked with Census tract SDOH measures. We included female patients with an incident diagnosis of invasive BC between 1/1/2007 and 12/31/2018 who received potential cardio-toxic treatment within 12 months. Guided by the Healthy People 2030 framework, 37 SDOH factors from five domains were selected. Continuous SDoH factors were categorized into three groups based on quartiles (1=less than Q1 (reference), 2=Q1 to Q3, 3=greater than Q3 or ‘high’). The study outcome was the probability of a cardiologist visit after initiating cardio-toxic treatment. Logistic regression with fixed effects provided covariate-adjusted odds ratios (AOR) and 95% confidence intervals (CI).

RESULTS: A total of 3,084 patients were included. The mean age was 71 years (SD=8). Among them, 85% were White, 10% were Black and 4% were Asian or Pacific Islander. A high tract-level unemployment rate (AOR: 0.60, 95%CI: 0.42-0.86) was associated with lower odds of a cardiologist visit while a high number of public transit trips for the Census tract was associated with higher odds of a cardiologist visit (AOR: 1.54, 95%CI 1.03-2.31). Statistically significant patient-level measures included comorbidity status and BC subtype.

CONCLUSIONS: Two (i.e., Economic Stability and Community / Social Context) SDOH domains out of five were associated with higher odds of a cardiologist visit among individuals diagnosed with BC. Additional research is needed to determine how these contextual factors shape outcomes.