Effect of Neighborhood Socioeconomic Factors on Readmissions and Mortality After Coronary Artery Bypass Grafting

Abstract

Social determinants of health, including neighborhood socioeconomic status (NSES), are increasingly being associated with disparate outcomes in those undergoing cardiac procedures. The objective of this study was to determine the effect of NSES on outcomes after coronary artery bypass grafting (CABG). Adults undergoing isolated CABG between July 2011 and December 2017 were retrospectively reviewed. Neighborhood median household income (NMI) and neighborhood high school graduation rate (NHS) were obtained by individual patient ZIP code from the American FactFinder Database. Primary outcome was 5-year all-cause mortality stratified by NMI quartile. Secondary end points included mortality risk by NHS, freedom and frequency of readmission, and mortality and readmission predictors. During the study period, 5243 patients underwent CABG. Increasing NMI quartile was associated with increasing age, male sex, white race, decreased diabetes prevalence, decreased active smoker status, and decreased lung disease (all P < .05). Although no difference in 30-day mortality was observed, lower NMI quartiles were associated with increased longitudinal mortality through 5 years (log-rank P < .01). Lower NMI quartile was associated with increased blood transfusions and sternal wound infections. Multivariable modeling demonstrated multiple complex associations between socioeconomic status variables (race, sex, age, NMI, and NHS) for mortality and readmission. NSES affects longer-term outcomes after CABG. Patient-focused NSES interventions and incorporation of NSES variables into prediction models may improve prediction and outcomes after CABG.