Background: Suboptimal adherence to long-term therapies is common and may potentially have adverse consequences on patient outcomes and healthcare costs.
Objective: To assess the association between adherence to levodopa/carbidopa/entacapone therapy and healthcare utilization and costs in patients with Parkinson’s disease.
Methods: A retrospective historical cohort study, conducted in the US, using a health insurance claims database, with data spanning from 1 January 2000 to 31 December 2005. Subjects included patients with Parkinson’s disease who were treated with levodopa (L), carbidopa (C) and entacapone (E) either as separate tablets (LC + E) or as a single-tablet formulation (LCE). The association between satisfactory adherence (defined as ‘proportion of days covered’ for LCE or LC+E during 1-year follow-up ≥80%) and healthcare utilization and costs was examined using multivariate regression to control for pretreatment adherence to LC and other patient characteristics.
Results: Compared with unsatisfactory adherence (n = 598), satisfactory adherence (n = 617) was associated with 39% fewer Parkinson’s disease-related hospitalizations (95% CI 20, 54; p<0.001), 47% lower all-cause inpatient costs (95% CI 18, 65; p = 0.004) and 18% lower all-cause total costs (95% CI 11, 24; p<0.001). On an adjusted basis, all-cause total costs were $US3508 less for those with satisfactory versus unsatisfactory adherence. In both the LC + E and LCE groups, satisfactory adherence was associated with significant reductions in all-cause hospitalizations (39% and 46%, respectively), and all-cause total costs (10% and 31%, respectively). The association between adherence and total healthcare costs was stronger for patients receiving LCE.
Conclusions: Better adherence to levodopa/carbidopa/entacapone therapy is associated with lower healthcare utilization and costs. Non-adherence to LCE is associated with a greater increase in costs than non-adherence to LC + E. Efforts should be made to ensure adherence to both therapies.
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Thomas E. Delea and May Hagiwara are employees of PAI (Policy Analysis, Inc.), an independent contract research organization, which has received research support and consulting fees from Novartis and other pharmaceutical companies. Thomas E. Delea has received honoraria from Novartis. Simu K. Thomas is an employee of Novartis, and owns stock/options in Novartis. Mark A. Stacy (Department of Neurology, Duke University School of Medicine, Durham, NC, USA) provided comments on the study design, analyses of data and writing of the manuscript. He has received research support and honoraria from and served as a consultant for Novartis. Meghan E. Gallagher (Novartis Pharmaceuticals) and Medicus International assisted the authors with the drafting, editing and proofing of this article. Funding for this study was provided by Novartis.
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Delea, T.E., Thomas, S.K. & Hagiwara, M. The Association between Adherence to Levodopa/Carbidopa/Entacapone Therapy and Healthcare Utilization and Costs among Patients with Parkinson’s Disease. CNS Drugs 25, 53–66 (2011). https://doi.org/10.2165/11538970-000000000-00000
- Healthcare Utilization
- Suboptimal Adherence
- Satisfactory Adherence
- Outpatient Pharmacy Claim