March 4, 2020

Real-world evidence empowers personalized decisions about weight-loss surgery

PCORnet Bariatric Study publishes latest clinical findings based on data from tens of thousands of bariatric surgery recipients

With its latest findings in JAMA Surgery on how many adults see their Type 2 diabetes go away and come back following weight-loss surgery, the PCORnet Bariatric Study now provides patients and their doctors with a more complete picture about the comparative benefits and risks of the two most commonly used surgical procedures. This real-world evidence enables patients in consultation with their providers to make more personalized decisions about which option would be best for them.

Drawing from the resources of PCORnet®, the National Patient-Centered Clinical Research Network, the PCORnet Bariatric Study is the largest study to date to compare the longer-used Roux-en-Y gastric bypass procedure and the newer and somewhat simpler approach called sleeve gastrectomy. Its findings are based on analyses of data from tens of thousands of bariatric recipients securely accessed via PCORnet.

The study, funded by the Patient-Centered Outcomes Research Institute (PCORI), previously reported findings on how these two procedures compare in weight loss and maintenance among adult patients in Annals of Internal Medicine along with rates of short-term health risks. Findings about rates of long-term problems requiring reoperations and other interventions appeared in JAMA Surgery.

Now with PCORI funding, the PCORnet Bariatric Study’s findings are being incorporated into a decision aid to empower patients, in consultation with their clinicians, to make personalized decisions about weight-loss surgery.

“More people with severe obesity should be having conversations about the role of bariatric surgery, which has been underused because of concerns about safety and weight regain,” said the study’s lead co-principal investigator David Arterburn, M.D., M.P.H., an internist and senior investigator at Kaiser Permanente Washington Health Research Institute in Seattle. “The results of the PCORnet Bariatric Study show that the overwhelming majority of patients maintain successful weight loss long term, especially after bypass. But bypass patients had a higher risk of subsequent operation and hospitalization.”

“As with many health care options, no one weight-loss surgical procedure is the best choice for every patient because tradeoffs are associated with each,” added co-principal investigator Kathleen McTigue, M.D., M.P.H., M.S., an associate professor of medicine and epidemiology at the University of Pittsburgh. “The choice requires personalized decision making that involves weighing the evidence about the pros and cons along with each person’s individual circumstances and preferences.”

Because of the large sample sizes that the researchers could assess through PCORnet, they could examine subgroups of people to assess whether certain characteristics improved or worsened their chance of weight loss success. They found that men, African Americans, Hispanics, people age 65 and older, and people with diabetes or lower body mass index (less than 50) tended to lose less weight than did other people in the study.

But these differences between patient groups were small—less than 3 percent differences in weight lost at 1, 3, and 5 years across groups—which was much less than the differences between the procedures.

Both PCORnet and PCORI emphasize patient guidance and partnership in studies. People who have had weight-loss surgery served as co-investigators and helped to refine the study question, select outcomes to study, interpret the findings and present the results. Neely Williams, M.Div., who has served as patient co-principal investigator for the study, noted that having gastric bypass has helped her, but this study’s results would have been helpful at the time of her surgery decision because she was not sure which procedure was best for her. Her pre-surgery screening did not offer details, and she didn’t know what questions to ask. As a partner in the study, she was able to call attention to things that may or may not have been considered by the people who were doing the research.

Developed with funding from PCORI, PCORnet harnesses the power of real-world data drawn from electronic health records, claims data and other sources to generate real-world evidence. The network enables researchers to access aggregated, de-identified data to conduct research on large sample sizes.