Income, race, and cardiovascular disease in female breast cancer survivors: evidence of moderated socioeconomic protection in the National Health Interview Survey (NHIS) 2019-2022

UNLABELLED: Cardiovascular disease (CVD) remains a leading cause of poor outcomes among breast cancer survivors. Treatment contributes to both acute and long-term CVD risk, but social determinants of health (SDoH), like economic deprivation, also compound vulnerability. This study examined the associations between poverty-to-income ratio (PIR) and self-reported CVD in a national sample of breast cancer survivors. METHODS: Using National Health Interview Survey (NHIS) data from 2019 to 2022, we examined sociodemographic characteristics, health behaviors, and comorbidities in a sample of 2745 female breast cancer survivors. We tested IPTW-adjusted logistic models for associations between PIR and CVD prevalence and interactions by race, age, years of survivorship, and delayed medical care. RESULTS: Higher income did not protect survivors equally. The protection of higher PIR was significantly modified by race/ethnicity (p < 0.0001). Higher PIR reduced the odds of CVD 92% among Black survivors, compared to 68% among White survivors, with no significant association among Asian survivors. The protection of higher PIR was greatest among survivors aged < 65 years and lessened progressively up to ≥ 85 years (p = 0.017). The overall interaction terms were non-significant (p > 0.05) for years of breast cancer survivorship and approached significance for delayed care-seeking. CONCLUSIONS: PIR emerged as a robust predictor of comorbid CVD with strongest protection among younger, racial/ethnic minority, and early-survivorship subgroups. IMPLICATIONS FOR CANCER SURVIVORS: Clinical CVD risk models in breast cancer remain underspecified when measures of economic status are excluded. These findings support extending clinical guidance for CVD prevention beyond the current 5-year threshold and integrating economic screening into survivorship care.