H. A. Rieken1, E. Garg1, T. N. Crawford1, A. Kroger2, T. Seidenschmidt2, C. Obringer2, A. Wang1 1Wright State University, Dayton, OH, USA 2Premier Health, Dayton, OH, USA
Introduction: Sleeve gastrectomy (SG) is currently the most common bariatric surgery performed in the United States. SG leads to significant and sustained weight loss. One of the most common questions patients ask during surgical consultation is what their expected weight loss will be. The Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program (MBSAQIP) created a risk/benefit calculator that estimates 30-day complication rate, weight loss out to 1 year, and resolution of comorbidities. Few studies have reported how the MBSAQIP calculator correlates with actual weight loss after SG. In addition, no study has investigated the calculator’s inter-user reliability. Thus, this study aims to compare the MBSAQIP calculator’s agreement with 6 month and 1 year weight loss after SG as well as to assess the calculator’s inter-user reliability.
Methods: A retrospective review of all adult patients who underwent laparoscopic SG from January to December 2019 was performed. All surgeries were conducted by a single surgeon. A power analysis determined that the minimum sample size needed to adequately power this study was 29 patients. Body mass index (BMI) data were collected at 6 months and 1 year. Descriptive statistics were computed using averages and standard deviations. A concordance correlation coefficient was used to assess agreement between predicted and actual BMI.
Results: 143 patients were eligible for analysis. Follow-up BMI was available for 92 patients at 6 months and 121 patients at 1 year. Baseline average BMI for the original 143 patients was 44.89 kg/m2 (SD 7.36). 81% were female, 19% were African American, and 31% had diabetes mellitus type II, of which one third were insulin-dependent. The rates of hypertension, reflux, hyperlipidemia, and sleep apnea were 52%, 45%, 31%, and 45% respectively. Average change in BMI at 6 months was 8.10 kg/m2 (SD 2.98) and at 1 year was 9.42 kg/m2 (SD 4.65). The MBSAQIP calculator had excellent agreement with actual BMI at 6 months (rc = 0.8824; 95% CI: 0.8314, 0.9187) and very good agreement at 1 year (rc = 0.7026; 95% CI: 0.6198, 0.7699) (Figure 1). Average predicted BMI at 6 months was 35.75 kg/m2, actual was 36.11 kg/m2 (SD 6.29). At 12 months predicted BMI was 32.77 kg/m2, actual was 35.53 kg/m2 (SD 6.74). Inter-user correlation was nearly perfect for 6 month (rc = 0.9998; 95% CI: 0.9997, 0.9999) and 1 year BMI (rc = 0.9992; 95% CI: 0.9989, 0.9994).
Conclusion: These findings suggest the MBSAQIP Risk/Benefit Calculator closely correlates with 6 month and 1 year weight loss in actual SG patients and is a useful tool to counsel patients on post-operative expectations. Additionally, inter-user reliability was excellent, suggesting this calculator is also easy to use.
