Cost-effectiveness of combining weight loss drugs and surgery

Newer weight loss drugs are cost effective in the long term only when combined with bariatric weight loss surgery, according to a study presented at the American College of Surgeons (ACS) Clinical Congress 2024 in San Francisco, California. Further, a second study presented at the meeting found that this increasingly popular class of weight loss drugs, called glucagon-like peptide-1 receptor agonists, or GLP-1 RA, appears safe and may be a novel approach to treating obesity when used before bariatric surgery.

Originally used to treat Type 2 diabetes, liraglutide (branded as Saxenda) and, more recently, semaglutide (branded as Wegovy) injections were approved by the U.S. Food and Drug Administration (FDA) for weight loss in patients with obesity or overweight and at least one weight-related health condition. These prescription medications lead to weight loss by mimicking hormones in the body that suppress appetite and increase a sense of fullness. 

People must use a GLP-1 RA indefinitely to maintain weight loss, said the first study's lead author, Joseph Sanchez, MD, a general surgery resident at Northwestern Medicine, Chicago.

GLP-1 RA are lifelong medications for obesity management that are not always covered by insurance and can cost some people $800 to $1,200 per month out-of-pocket. But we didn't know how these medications compared in cost effectiveness with the gold-standard obesity management option, bariatric surgery." 

Dr. Joseph Sanchez, MD, general surgery resident at Northwestern Medicine, Chicago

Anne Stey, MD, FACS, the study's senior investigator and an assistant professor of surgery at Northwestern University Feinberg School of Medicine, Chicago, emphasized the importance of this information.

"As evidence of health benefits of GLP-1 RA continues to come out, insurance companies will have to decide whether they will cover these medications and in which case scenarios," Dr. Stey said. "Understanding if and how these different obesity management options are cost effective is critical to ensure as many people have access to these medications as possible."

Cost-effectiveness study

Dr. Sanchez and colleagues performed a cost-effectiveness analysis of GLP-1 RA therapy alone and bariatric surgery alone -; either gastric bypass or sleeve gastrectomy. They also studied the cost effectiveness of bariatric surgery in conjunction with treatment with GLP-1 RA to prevent weight regain. 

The investigators predicted the costs of each of these treatments until death (up to 50 years) for thousands of patients from different clinical trial findings around the United States. The researchers considered a treatment to be cost effective if the total cost was less than $100,000 per quality-adjusted life year (QALY). A QALY is one adequately healthy year of life a patient could gain from treatment.

At $17,400 to $22,850, the estimated cost of bariatric surgery exceeded the average yearly cost of $9,360 to $16,200 for GLP-1 RA, the researchers found. However, compared with these medications alone, bariatric surgery added approximately two QALYs and would save a patient more than $9,000 to earn a year of quality life. GLP-1 RA combined with bariatric surgery would save more than $7,200 per QALY versus surgery alone and added more than five QALYs. 

"Undergoing bariatric surgery is more cost effective in the long run than maintaining these medications for the remainder of an individual's life," Dr. Sanchez said. "The critical role for these medications from a cost-effectiveness perspective is to use these medications to address weight regained after bariatric surgery."

These results could change later, he said, if the cost of these medications decrease or if new, lower-priced weight loss medications become available. However, he added that the cost would have to decrease by nearly 75%.

GLP-1 RA used before surgery

A study from Indiana University (IU) School of Medicine in Indianapolis found that the use of GLP-1 RA in the year before bariatric surgery has increased more than threefold since 2018 -; from 8% to 24%. 

Some researchers have proposed using GLP-1 RA medications before bariatric surgery to help lower the weight of patients with a body mass index (BMI) greater than 50, which can make the operation more complex, said Tarik Yuce, MD, MS, the study's senior investigator, an ACS Associate Fellow, and an assistant professor of surgery at IU School of Medicine. A BMI of 40 or greater is considered severe obesity.

"Losing weight can perhaps make the surgery easier and safer, so that's an exciting potential avenue for these medications," Dr. Yuce said.

According to Qais AbuHasan, MD, an IU School of Medicine research fellow and the study's lead author, the study's purpose was to determine whether any adverse effects occur with the use of GLP-1 RA before bariatric surgery. Patients may have used the medication to treat diabetes, to lose weight, or both.

The research team studied outcomes for 2,169 patients who underwent bariatric surgery at three IU-affiliated hospitals from 2018 through 2023. Outcomes evaluated included differences in 30-day hospital readmissions, emergency department visits, and complications for patients who preoperatively used GLP-1 RA (293 patients) and patients who did not (1,876 patients).

Dr. AbuHasan reported no statistically significant differences between treatment groups in these short-term outcomes or in the percentage of total weight loss one year after surgery. Patients who used GLP-1 RA preoperatively lost a median of 25.5% of their total weight one year after the operation, and patients who did not use these medications lost 27.3% of total weight.

"It might be safe to use GLP-1 RA in the preoperative period," he concluded. "But we need to investigate further to determine whether factors such as the dose and duration of treatment may or may not lead to any differences in outcomes."

Other co-authors of the study on GLP-1 RA use before surgery are Wendy Li, MD; Charles Burney, MD; Luke Funk, MD, FACS; Jane Holl, MD, MPH; Don Selzer, MD, FACS; and Dimitrios Stefanidis, MD, PhD, FACS. 

Co-authors for the study on the cost effectiveness of bariatric surgery and GLP-1 receptor agonists are Alexander Lundberg, PhD; Whitney Jones, MD, MBA; Catherine Valukas, MD, MS; Tara Lagu, MD, MPH; and Ezra N. Teitelbaum, MD, FACS.