Provider Care Team Segregation and Operative Mortality Following Coronary Artery Bypass Grafting
John M. Hollingsworth, Xianshi Yu, Phyllis Yan, Hyesun Yoo, Dana A. Telem, Ekow N. Yankah, Ji Zhu, Akbar K. Waljee, Brahmajee K. Nallamothu
Abstract
Background: Black patients die more frequently following coronary artery bypass grafting (CABG) than their White counterparts for reasons not explained by disease severity or comorbidity. We analyzed medical claims to determine the contribution of provider care team segregation within hospitals contributes to this inequity. Methods: We analyzed national Medicare data, identifying beneficiaries who underwent coronary artery bypass grafting at hospitals where procedures were performed between 2008 and 2014 (n=12 414). After determining the providers who delivered perioperative care, we examined the extent to which Black and White patients were cared for by unique provider care team networks within the same hospital. We evaluated whether a lack of overlap in composition of these networks treating Black versus White patients (ie, high segregation) was associated with higher 90-day operative mortality among Black patients. Results: Levels of provider care team segregation were moderate (median, 0.493) and varied across hospitals (interquartile range, 0.439–0.542). Compared with patients treated at low segregation hospitals, those treated at medium and high segregation hospitals were more likely to be older, white, and undergo an elective procedure ( P <0.01 for each comparison). After controlling for these and other differences, Black patients treated at high segregation hospitals had numerically higher mortality than those treated at low segregation hospitals (6.4% [95% CI, 3.4%–11.6%] versus 4.4% [95% CI, 2.3%–8.1%], respectively), but this difference was nonsignificant ( P =0.495). In contrast, White patients treated at high segregation hospitals had significantly lower mortality than those treated at low segregation hospitals (4.9% [95% CI, 4.1%–5.8%] versus 7.5% [95% CI, 5.8%–6.3%]; P =0.007). Conclusions: There are often unique systems of provider care teams, which treat Black patients but do not overlap with those of White patients undergoing coronary artery bypass grafting. Provider care team differences may contribute to surgical outcome variability between Black and White patients.