Higher Edmonton Obesity Staging System scores are independently associated with postoperative complications and mortality following bariatric surgery: an analysis of the MBSAQIP

Introduction Bariatric surgery is an evidence-based approach for sustained weight loss in patients with severe obesity. The most common procedures in North America are the laparoscopic sleeve gastrectomy (LSG) and laparoscopic Roux-en-Y gastric bypass (LRYGB). The Edmonton Obesity Staging System (EOSS) is a tool that assigns patients a score of 0 to 4 according to their obesity-related comorbidities and functional status. Previous research demonstrates that increasing EOSS score is associated with overall non-operative mortality risk. Objective We sought to assess the association of the EOSS with major 30-day postoperative complications following LSG or LRYGB. Methods Primary LSG or LRYGB patients were identified from the Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program data registry. Patients were assigned EOSS scores according to their comorbidities and functional limitations extracted from the database. Multivariable logistic regression analysis was conducted to evaluate the relationship between EOSS score, age, sex, BMI, type of procedure, or operative time with 30-day major complications. Results From 2015 to 2017, 430,238 patients (79.4% female) who underwent primary LSG or LRYGB were identified. The relative frequencies of patients by EOSS score were: 0 and 1 (23.9%), 2 (62.8%), 3 (10.5%), and 4 (2.9%). Mean preoperative BMI was 45.4 (SD 7.9) kg/m 2 and mean age was 44.6 (SD 12.0) years. The overall 30-day major complication rate was 3.5%. EOSS 2, 3, and 4 were significantly associated with major complications. The strongest associations with major complications were EOSS 4 (OR 2.30; 95% CI 2.11–2.51, p