Income and Geographic Disparities in in-Hospital Mortality Following Cardiovascular Procedures: Evidence From the...

To examine whether income- and geography-related disparities in in-hospital mortality after major cardiovascular procedures arise from differences in patient acuity, hospital characteristics, or inequities within hospitals.

This observational study analyzed national data on eight major cardiovascular procedures performed between 2016 and 2022. We used multivariable logistic regression with progressive adjustment for demographics, clinical severity (All Patient Refined Diagnosis Related Groups [APR-DRG] risk and severity scores), and hospital characteristics.

We analyzed secondary data from the National Inpatient Sample including 1,120,235 discharges (weighted N = 5,906,795) representing adults undergoing percutaneous coronary intervention, coronary artery bypass grafting, carotid endarterectomy/stenting, surgical valve replacement, transcatheter valve procedures, non-carotid endarterectomy, aneurysm repair, or peripheral bypass. Patient income was proxied using ZIP code-level median household income quartiles. Geographic location was classified as large metropolitan (≥ 1 million population), smaller metropolitan (50,000-999,999), or non-metropolitan.

Lowest-income patients presented with mean APR-DRG risk scores 0.15-0.25 points higher than highest-income patients. After full adjustment with hospital fixed effects, in-hospital mortality was 0.67% points higher (95% CI: 0.08-1.26) among lowest-income patients. Geographic patterns were complex: after adjusting for hospital characteristics, non-metropolitan location was associated with 0.48% points higher mortality, though this was not statistically significant (95% CI: -0.01 to 0.97), and smaller metropolitan areas with 1.03% points higher mortality (95% CI: 0.30-1.76). Between-hospital differences explained 11.6% of mortality variance.

Socioeconomic and geographic disparities in mortality following major cardiovascular procedures persist after adjustment for clinical and hospital factors. These disparities remain, with slightly larger point estimates, in within-hospital analyses, suggesting that hospital-level differences alone do not account for observed inequities. Interventions should address both social determinants and intra-hospital inequities. Multilevel interventions targeting both social determinants and within-hospital processes may be needed.