4-Year Cost Trajectories in Real-World Patients Matched to the Metabolic Profiles of Trial Subjects Before/After Treatment with Phentermine-Topiramate

Abstract

Objective: Our objective was to estimate 4-year healthcare costs associated with the metabolic profile of patients before and after 1 year of treatment with phentermine (15 mg) and topiramate extended-release (92 mg) [phentermine-topiramate ER]. Design and Methods: Using a medical records database, we created two patient cohorts reflecting metabolic profiles of subjects before and after phentermine-topiramate ER therapy during the 1-year CONQUER trial. We matched database patients with trial subjects by age, sex, body mass index (BMI), and hypertension, glycemic, and triglyceride status. We collected real-world data on emergency department and outpatient visits, hospitalizations, and drug prescriptions over 4 years, linking them to reimbursements to estimate US private insurance costs for post-trial (n = 2295) versus pre-trial intention-to-treat (ITT) patients (n = 2295). Secondary analysis assessed responders (completers losing ≥5 % body weight [n = 1285]). Results: Over 4 years, the mean cost per patient in the post- versus pre-trial ITT-group was $US32,432 versus $US34,725 (mean difference −2292; 95 % confidence interval [CI] –4776 to 209). In responders, corresponding costs were $US30,558 versus $US33,936 (mean difference –3378; 95 % CI –6496 to –464). Costs for post- versus pre-trial responders were lower for outpatient visits, emergency visits, and medications (all P < 0.05). Conclusion: Excluding treatment cost and potential side effects, patients matched to profiles of phentermine-topiramate ER responders had lower costs than patients matched to pre-treatment profiles.