Does the MBSAQIP Bariatric Surgical Risk/Benefit Calculator Accurately Predict Weight Loss in Adolescents?

The Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program (MBSAQIP) online calculator incorporates individual patient data to predict weight loss up to 1 year after MBS, but it was derived from an adult database and has not been validated in younger cohorts. This study evaluates the accuracy of this calculator for adolescent MBS patients and explores patient factors which may be associated with prediction inaccuracy.

We include patients age ≤ 21 who underwent laparoscopic sleeve gastrectomy at two major academic institutions from 2013 to 2023. Data were stratified between patients age < 18 and 18-21. The calculator's predictions were compared to actual weight loss values at 1 year. Relationships between various preoperative variables and the difference between predicted and actual weight loss were assessed using correlation, regression, and t-tests.

There were 265 patients, with 176 age < 18. The correlation coefficients for predicted and actual weight loss were 0.48 for patients age < 18 and 0.38 for patients 18-21. On average, the proportion of predicted weight loss actually attained at 1 year was 0.73. There were no statistically significant associations between calculator inaccuracy and patient age, sex, preoperative body mass index, or area deprivation index (all p > 0.05).

The MBASQIP calculator predictions show weak to moderate correlation with actual weight loss at 1 year and should be used with caution when counseling pediatric patients considering MBS. This project underscores the importance of building multi-institutional collaborations and databases specific to the pediatric MBS context.