GLP-1 drugs shown cost-effective for knee osteoarthritis and obesity, but MBS may be the best option from a clinical and economic perspective

A study led by investigators at Mass General Brigham has found that adding semaglutide and tirzepatide to usual care represents a cost-effective treatment strategy for people with knee osteoarthritis and obesity, with tirzepatide providing greater health benefits at lower cost compared to semaglutide. However, the researchers found that for persons with BMI>35 kg/m2, RYGB would offer the best return on investment for cost-effectiveness thresholds.

“Weight loss can relieve joint pain, but semaglutide and tirzepatide are expensive and most insurance plans don’t cover weight loss medications. This means that many patients can’t afford these medications,” explained senior author, Dr Elena Losina, from the Department of Orthopaedic Surgery at Brigham and Women’s Hospital. “This is why a formal economic analysis is valuable. It gives payers and policymakers the data they need to make informed coverage decisions and improve access to these weight loss treatments. Our goal is to ensure that payers and policymakers have the evidence they need to make informed decisions about coverage.”

The study was funded by Arthritis Foundation and National Institute of Arthritis, Musculoskeletal and Skin Diseases. The investigators used OApol, a validated and widely published computer simulation model, to conduct a cost-effectiveness analysis comparing the two GLP-1 drugs as well as two other common weight loss interventions: bariatric surgery and lifestyle modifications.

They found that tirzepatide offered somewhat better value than semaglutide and would be the preferred option between the two drugs for most patients. For eligible and willing patients, bariatric surgery, which provides sustained benefits, may be the best option from a clinical and economic perspective.

In the primary analysis excluding surgical strategies, the researchers found that UC led to 9.59 QALYs compared with 9.75 for diet and exercise, 10.48 for semaglutide, and 10.68 for tirzepatide. Adding diet and exercise to UC resulted in an ICER of $25,400 per QALY, whereas adding tirzepatide produced an ICER of $57, 400 per QALY. Tirzepatide provided greater clinical benefit at lower costs when analyzed incrementally compared to semaglutide.

In the secondary analysis, the researchers found that for persons with BMI>35 kg/m2, RYGB would offer the best return on investment for cost-effectiveness thresholds above $30,700 per QALY, which may stem from the long-term weigh maintenance seen after MBS, compared to GLP-1s.

The researchers said these findings should inform discussions between clinicians and patients on the differences between these weight loss interventions, their potential benefits and harms, and currently available knee osteoarthritis care options for persons with BMI>30 kg/m2 and symptomatic knee osteoarthritis.

Limitations of this analysis include its reliance on data integrated from multiple sources. In addition, conducting this study required researchers to make assumptions about the duration of time patients would remain on these medications, which may affect the findings.

“Osteoarthritis substantially reduces quality of life due to debilitating pain and limited mobility. Obesity has been shown to shorten life expectancy,” said Losina. “Offering these drugs to patients with knee osteoarthritis and obesity improves both measures.”

This study was funded by the Arthritis Foundation and National Institutes of Health.

The findings were reported in the paper, ‘The Cost-Effectiveness of Semaglutide and Tirzepatide for Patients With Knee Osteoarthritis and Obesity’, published in the Annals of Internal Medicine. To access this paper, please click here