R Zhou, MD, L Ying, PhD, J Valle, J Moore, APRN, G Nazdam, MD, K Roberts, MD, S Ghiassi, MD, J Morton, MD, A Duffy, MD. Yale University
Introduction: Obesity is one of the most significant health challenges faced today. Recently, the American Society for Metabolic and Bariatric Surgery has released a Bariatric Surgical Risk/Benefit Calculator (“MBSAQIP Calculator”), an online tool in which patients and providers can input patient preoperative information and predict the 30-day complication risk as well as 1-year weight loss. In this study, we seek to validate our institutional data with the national database. Furthermore, we investigated patient factors that influence poor response to bariatric surgery.
Methods: A retrospective review of all prospectively collected data of bariatric surgeries performed at Yale New Haven Hospital from 2017 to 2018 was conducted. By entering data into the MBSAQIP Calculator, the 1-year predicted Body Mass Index (BMI) was calculated and compared to the weight loss actually experienced by the patients. Statistical analysis was be performed using unpaired t-test with Welch’s correction and Strata.
Results: Data was obtained from 327 patients. The average difference between the actual and predicted weight loss at 1-year was 3.6 BMI points. Figure 1 displays a strong overlap between the predicted and actual BMI recorded at 1-year. Figure 2 demonstrates a scatter plot of actual compared to predicted BMI at 1 year (R=0.6, P=0.003). Figure 3 shows a bell-shaped distribution of actual weight loss plotted against predicted BMIs. We examined the outliers with a comparison of weight loss for those patients who’s BMI fell within 5 points of the predicted versus those who’s BMI recorded above 5 points. Figure 4 reveals that those patients who did not respond as well to bariatric surgery, i.e. had higher than 5 BMI points than predicted, had significantly higher preoperative BMI (46.1 vs 43.6, P=0.008).
Conclusions: The MBSAQIP calculator is a useful tool to guide surgeons with decision making and informed consent. Our institution’s 1-year weight loss data correlated closely with that predicted by the calculator. Looking at the outliers, we found that patients who did not meet the predicted weight loss had significantly higher preoperative BMI. This may alter preoperative discussions with super-obese patients in regards to expected weight loss after surgery and warrant further investigations with the national database to develop modifications of the calculator for the super-obese. In addition, with this validation of the calculator in our patient population, further studies can be performed to compare weight loss between primary bariatric procedures to the outcomes after revisions.
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Figure 1.
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Figure 2.
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Figure 3.
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Figure 4.
This abstract was accepted for Podium presentation at the 2020 SAGES Virtual Meeting in the Bariatric topic. Its program number was: S023 and its Abstract ID was: 100875