Mediators of racial disparities in postoperative outcomes among patients undergoing complex surgery

Background: This study sought to quantify the direct and indirect effects of race on postoperative outcomes after complex surgery. Methods: Medicare patients who underwent abdominal aortic aneurysm (AAA) repair, coronary artery bypass grafting (CABG), lung resection or colectomy were identified (2014-2018). Generalized structural equation modelling was utilized to quantify the direct and indirect effects of race on Textbook outcome (TO). Results: Among 930,033 patients, 46.8% of patients achieved a TO, with Black patients less likely to achieve a TO (referent: White; Black: OR 0.72, 95% CI 0.70-0.73). Notably, 32.3% of the disparities in TO were attributable to race itself, while 67.7% was explained by other factors. Specifically, residential segregation accounted for 39.4% of the lower TO rates among Black patients, while 21.0% was attributable to a high comorbidity burden. Conclusions: These data highlight the need to target structural racism as a policy priority to promote a more equitable healthcare system.