PCORnet Bariatric Study

Project Summary: The use of bariatric surgery as a treatment for severe obesity has increased dramatically over the past two decades, but there have been few high-quality, long-term studies comparing the outcomes of different procedures. Prior studies have also not been large enough to examine differences in outcomes across important patient subgroups, including older adults (≥65 years of age) and racial/ethnic minorities. Research on the outcomes of adolescent bariatric surgery is even more limited and mostly consists of studies of short duration. More studies are needed in larger, more broadly representative samples to help inform patient and provider decisions about the optimal choice of bariatric surgical procedure in various populations.

The main goal of the proposed study is to provide accurate estimates of the one-, three-, and five-year benefits and risks of the three most common bariatric procedures—Roux-en-y gastric bypass, adjustable gastric banding, and sleeve gastrectomy—with a focus on outcomes that are important to adults and adolescents with severe obesity: 1) changes in weight, 2) rates of remission and relapse of diabetes, and 3) risk of major adverse events. The study has two additional goals: 1) the development of infrastructure—in the form of study processes and procedures—to support future comparative effectiveness studies using the PCORnet distributed research network, and 2) the identification of patient preferences and opinions about (a) whether to undergo bariatric surgery; (b) which bariatric procedure to utilize; and (c) the delivery of follow-up care after bariatric surgery through a series of focus groups involving adults and children with severe obesity. Patients and other stakeholders have been fully engaged in the development of this proposal and will be engaged in all stages of the protocol development, including formulating the research questions, selecting outcomes that are of interest to the study population, identifying methods to address these outcomes, monitoring study conduct, and designing and implementing dissemination plans.

Our study will involve 10 of PCORnet’s Clinical Data Research Networks (CDRNs) including 53 healthcare organizations and more than 60,000 bariatric patients, with 50 percent gastric bypass, 10 percent gastric banding, and 40 percent sleeve gastrectomy procedures. This study will also include more than 900 adolescent bariatric patients (the largest adolescent cohort ever) and more than 17,000 patients with diabetes. Given our large study population, we will have more than sufficient statistical power to address all of our primary aims. Our study is particularly timely because the sleeve gastrectomy procedure has rapidly grown in popularity in the United States (introduced in the late 2000s as a stand-alone procedure, it currently represents more than 50 percent of all procedures in our 10 PCORnet CDRNs), yet it lacks long-term data comparing its outcomes to the more well-established procedures.

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