Validation of the cumulative deficit theory in bariatric surgery: new bariatric frailty score is associated with non-home discharge, prolonged hospital stay and mortality in the era of fast-track bariatric surgery

Background: Frailty is a wasting disorder that can coexist with obesity, thus, the term "obese frailty syndrome". Frailty can be measured using the cumulative deficit model demonstrated in the Canadian Study of Health and Aging-Frailty Index (CSHA-FI).

Objectives: To develop a Bariatric Frailty Score (BFS) to predict 30-day adverse postoperative outcomes.

Setting: University hospital.

Methods: Patients (aged 18-80 yr) who underwent sleeve gastrectomy (SG) and Roux-en-Y-gastric bypass (RYGB) were included using the 2015-2018 Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program (MBSAQIP) database. Fourteen variables of the CSHA-FI were mapped onto 10 variables of MBSAQIP (each component equal 1 point). Correlations and multivariate logistical regression analysis were performed between BFS and 4 postoperative outcomes (non-home discharge, mortality, prolonged hospital stay, and ICU admissions). Finally, a propensity matching score (PSM) between low BFS (0-4) and high BFS (5-10) was performed.

Results: In 650,882 patients (72% SG, 28% RYGB), the increasing BFS was strongly correlated on linear regression. In the multivariate analysis, scores of 5, 6, and 7 strongly predicted the 4 postoperative outcomes of interest. After the PSM, high BFS (5-10) was associated with an increased rate of postoperative complications in SG and RYGB groups.

Conclusion: Our BFS is a better predictor of non-home discharge, prolonged hospital stay, mortality, and unplanned ICU admission compared with age >60 years or American Society of Anesthesiologists (ASA) score of IV-V. Our study validated the cumulative deficit theory in bariatric surgery, implying that the cumulative effects of the existing co-morbidities are higher than if these co-morbidities were simply added.