Racial disparities in reasons for mortality following bariatric surgery

Metabolic and bariatric surgery (MBS) remains a safe and effective treatment for patients with severe obesity. Recent studies have highlighted racial disparities in perioperative outcomes, including up to a twofold higher mortality rate in non-Hispanic black (NHB) (vs. non-Hispanic white (NHW)) patients. Causality for these disparate outcomes remains unclear and largely unexplored.

Our study aim was to determine reasons for mortality among racial and ethnic cohorts and MBS patients.

Academic Hospital.

Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy (SG) cases were identified using the 2015 to 2018 Metabolic and Bariatric Surgery Accreditation and Quality Improvement Project (MBSAQIP) database using current procedural (CPT) codes 43,664, 43,645, and 43,775. Multivariate regression analyses were performed to determine independent predictors of overall and bariatric-related mortality. Reasons for mortality were identified and compared between racial and ethnic cohorts.

Of 650,903 RYGB and SG cases, 512,041 were included in our analysis (73% SG). For the entire cohort, all-cause and bariatric-related mortality rates were 0.095% and 0.05%, respectively. Age, male gender, ASA 4, functional status, therapeutic anticoagulation, smoking, COPD, and RYGB were independently associated with both overall and bariatric-related mortality. NHB had increased odds (2.13, p < 0.001) of bariatric-related mortality. Compared to NHW patients (13.3%), venous thromboembolic (VTE) complication was the most common reason for overall mortality in NHB (27.8%) and Hispanic (25%) patients (p < 0.001). VTE-related mortality directly associated with the bariatric procedure was also higher in NHB (34.6%) and Hispanic (33.3%) (vs. NHW 21.0%) patients (p 0.05). When stratified by procedure, mortality causes in RYGB cases were similar between racial and ethnic cohorts. In the SG cohort, the proportion of VTE-related mortality varied significantly (p 0.043) between NHB (39.2%), Hispanic 40.0%, and NHW (20.5%) patients.

There are racial and ethnic differences in causes of mortality following bariatric surgery. The predominant cause of overall and bariatric-related mortality in NHB bariatric surgery patients is postoperative venous thromboembolism. More granular MBSAQIP data capture is needed to determine the role of patient risk versus practice patterns in these disparate outcomes.