The effect of socioeconomic factors on patient outcomes in cardiac surgery

Healthcare delivery is heterogenous; the reasons for this are numerous and complex. Patient-specific factors including geography, income, insurance status, age, and gender have been shown to bias surgical outcomes. Utilizing a prospectively collected all-payer database, we aim to evaluate the influence of socioeconomic factors on mortality and length of stay (LOS) after common cardiac surgical procedures.

We utilized the National Inpatient Sample, Healthcare Cost and Utilization Project, Agency for Healthcare Research and Quality for the year 2019. We included patients undergoing coronary artery bypass grafting (CABG), aortic valve replacement (AVR), transcatheter aortic valve replacement (TAVR), and combined AVR/CABG using the 10th revision of the International Classification of Diseases procedure codes. AVR and CABG were combined into a separate cohort as this was felt to represent a different pathology than isolated valvular or coronary arterial disease. Baseline demographics were summarized. Multivariable regression was performed within each procedure group to model the odds of in-hospital mortality and hospital LOS with age, sex, insurance, zip-code median household income, and location as predictors.

Baseline patient characteristics including gender, income, geography, and payer status were similar between CABG, AVR, and AVR/CABG. TAVR patients had a higher proportion of female sex and Medicare as the primary payer, with an overall greater age. Multivariable Cox proportional hazards regression found that higher income was strongly associated with decreased LOS following AVR and CABG, and moderately associated in TAVR and AVR/CABG. Private insurance was associated with a decreased LOS in patients undergoing CABG, AVR, TAVR, and AVR/CABG. Female sex and increased age were associated with increased odds of mortality in TAVR, CABG, and AVR/CABG. Private insurance was associated with a decreased odds of mortality in patients undergoing AVR.

These findings reveal significant disparities in patient outcomes after routine cardiac operations that are associated with socioeconomic status. Patients who did not have private insurance or had lower incomes were found to be at risk for increased LOS. Women were at a higher risk of mortality for several operations, a finding which has been previously described elsewhere. Private insurance conveyed a decreased odds of mortality in patients undergoing AVR. This data set serves to highlight differences in healthcare outcomes based on a variety of socioeconomic, geographic, and other inherent factors. Additional research is needed to identify the mechanisms behind these disparities with the goal of providing equitable care to all patients.