Direct and Indirect Effects of Race and Socioeconomic Deprivation on Outcomes After Lower Extremity Bypass

Abstract

Objective: To evaluate the potential pathway, through which race and socioeconomic status, as measured by the social deprivation index (SDI), affect outcomes after lower extremity bypass chronic limb-threatening ischemia (CLTI), a marker for delayed presentation. Background: Racial and socioeconomic disparities persist in outcomes after lower extremity bypass; however, limited studies have evaluated the role of disease severity as a mediator to potentially explain these outcomes using clinical registry data. Methods: We captured patients who underwent lower extremity bypass using a statewide quality registry from 2015 to 2021. We used mediation analysis to assess the direct effects of race and high values of SDI (fifth quintile) on our outcome measures: 30-day major adverse cardiac event defined by new myocardial infarction, transient ischemic attack/stroke, or death, and 30-day and 1-year surgical site infection (SSI), amputation and bypass graft occlusion. Results: A total of 7077 patients underwent a lower extremity bypass procedure. Black patients had a higher prevalence of CLTI (80.63% vs 66.37%, P < 0.001). In mediation analysis, there were significant indirect effects where Black patients were more likely to present with CLTI, and thus had increased odds of 30-day amputation [odds ratio (