乌鸦传媒

DALLAS -- Sticking with anti-obesity medications may depend on certain factors, according to a retrospective cohort study.

In a sample of patients who filled at least one prescription for an anti-obesity medication, 44% persisted with the drug at 3 months, which dropped to 33% at 6 months and only 19% at 1 year, reported Hamlet Gasoyan, PhD, of the Cleveland Clinic Lerner College of Medicine of Case Western Reserve University in Cleveland, during the ObesityWeek annual meeting.

Some non-persistence may result from limitations in insurance coverage or certain precertification criteria, such as step therapy, Gasoyan said. "Better understanding non-persistence with anti-obesity medications may help in projecting costs associated with coverage and in addressing barriers to continued use of the medications."

Looking at naltrexone-bupropion, phentermine-topiramate (Qsymia), orlistat (Xenical, Alli), liraglutide (Saxenda), and semaglutide (Wegovy), persistence declined with all five medications over 1 year, though this varied significantly by medication.

After adjusting for age, sex, race/ethnicity, payer type, Area Deprivation Index quartile, and Charlson Comorbidity Index, those who used semaglutide had more than four times greater odds of continuing the medication at 1 year (OR 4.26, 95% CI 3.04-6.05, P<0.001), while those using naltrexone-bupropion were least likely to continue, with borderline significance (OR 0.68, 95% CI 0.46-1.00, P=0.049).

When the researchers looked only at patients on private insurance, a similar pattern emerged. Patients using semaglutide had greater persistence at 1 year (OR 3.69, 95% CI 2.55-5.40, P<0.001), and those using naltrexone-bupropion had the least persistence (OR 0.64, 95% CI 0.42-0.97, P=0.03).

Looking at insurance carrier, with Aetna as the reference, patients on the Cleveland Clinic Employee Health Plan had the lowest odds of persistence (OR 0.42, 95% CI 0.22-0.80, P=0.009). No significant differences in persistence were observed for patients with insurance from Blue Cross Blue Shield, Cigna, Medical Mutual Ohio, or United Healthcare, but those with other commercial carriers also had lower odds of persistence (OR 0.52, 95% CI 0.27-0.98, P=0.046).

"We're already getting some anecdotal evidence that some employers and health plans are starting to think about restricting coverage for anti-obesity medications," often citing the unsustainable cost burden of GLP-1 receptor agonists and weight regain due to non-persistence, Gasoyan told attendees.

Another predictor of persistence at 1 year after adjustment was weight loss at 6 months, based on a subset of 505 patients. For every 1% of body weight lost at 6 months, patients had 6% greater odds of persistence at 1 year (OR 1.06, 95% CI 1.03-1.09, P<0.001).

"It makes sense that people who achieve weight loss would be more likely to be persistent, and that held true," Gasoyan said.

Laura Schmidt, PhD, MSW, MPH, of the University of California San Francisco, pointed to the substantial selection bias in the study sample and the corresponding relative impact of drug shortages on this population.

"In order to stay in the study, people had to have private insurance, but when you're thinking about interpreting results like that, you have a very, very special sample of people," Schmidt told 乌鸦传媒. Because Cleveland Clinic is a large institution, "some of the people could have been buffered from the drug shortages," which was not controlled for in the study.

She also noted that potential differences could exist between those who persist with medication and those who don't that weren't captured in the data. Those taking semaglutide, for example, were likely told by their doctors that they will regain weight if they stop taking the drug.

"There are big policy implications for a study like that because it's making the case for private insurance to cover it," Schmidt said, adding that she's skeptical that this study can overcome its limitations for that purpose.

For this study, Gasoyan and colleagues analyzed electronic health record data from all 1,911 adult patients at the Ohio and Florida Cleveland Clinic locations who had a body mass index (BMI) of at least 30 and filled an initial prescription for an anti-obesity medication between July 2015 and June 2022, excluding patients who were pregnant, had cancer, or underwent bariatric surgery within 3 years of the first prescription fill.

They also looked at Surescripts records of prescriptions dispensed between January 2015 and July 2023.

Most of the patients were women (75%) and were privately insured (84%); average age was 44, and median BMI was 38. A majority were white (76%), 16% were Black, and 4.5% were Hispanic. A third of the patients filled a prescription for naltrexone-bupropion, 25% had a prescription for semaglutide, 26% had a script for phentermine-topiramate, 14% for liraglutide, and 0.9% for orlistat.

The researchers defined 3-month persistence as filling the first prescription and then refills over 3 months until patients had a gap of more than 15 cumulative days. Six-month persistence lasted until a 45-day gap, and 12-month persistence until a 90-day cumulative gap.

The findings were limited by shortages of anti-obesity medications that occurred during the study period. Gasoyan also acknowledged that the dataset wasn't able to capture patient-provider-related factors, such as discontinuing a medication because of inadequate weight loss.

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