Purpose: Individual weight loss outcomes after bariatric surgery can vary considerably. As a result, identifying and assisting patients who are not on track to reach their weight loss goals can be challenging.
Materials and methods: Using a bariatric surgery outcomes calculator, which was formulated using a state-wide bariatric-specific data registry, predicted weight loss at 1 year after surgery was calculated on 658 patients who underwent bariatric surgery at 35 different bariatric surgery programs between 2015 and 2017. Patient characteristics, postoperative complications, and weight loss trajectories were compared between patients who met or exceeded their predicted weight loss calculation to those who did not based on observed to expected weight loss ratio (O:E) at 1 year after surgery.
Results: Patients who did not meet their predicted weight loss at 1 year (n = 237, 36%) had a mean O:E of 0.71, while patients who met or exceeded their prediction (n = 421, 63%) had a mean O:E = 1.14. At 6 months, there was a significant difference in the percent of the total amount of predicted weight loss between the groups (88% of total predicted weight loss for those that met their 1-year prediction vs 66% for those who did not, p < 0.0001). Age, gender, procedure type, and risk-adjusted complication rates were similar between groups.
Conclusion: Using a bariatric outcomes calculator can help set appropriate weight-loss expectations after surgery and also identify patients who may benefit from additional therapy prior to reaching their weight loss nadir.
Keywords: Bariatric surgery; Patient-reported outcomes; Weight loss outcomes diabetes.