Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| [b] Division of General Internal Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
Center for Public Health Initiatives, University of Pennsylvania, Philadelphia, PA, USA
Leonard Davis Institute of Health Economics, University of Pennsylvania, Philadelphia, PA, USA
| [e] AbbVie Inc., North Chicago, IL, USA
Correspondence to: Nabila Dahodwala, MD, MS, Department of Neurology, Perelman School of Medicine, University of Pennsylvania, 330 South 9th Street, 2nd Floor, Philadelpia, PA 19107, USA. E-mail: [email protected].
Abstract: Background:Increasing doses of oral antiparkinson medications are indicated in advanced Parkinson’s disease (PD), but little is known about sustainment of high-dose regimens. Objective:To investigate sustainment of high-dose oral medication regimens in Medicare beneficiaries with incident advanced PD. Methods:This retrospective cohort study utilized 100%fee-for-service Medicare claims from 2011–2013. We identified advanced PD using a pharmacy claims-based proxy and selected patients who initiated a new high-dose oral medication regimen (daily levodopa equivalent dose [LED] >1000 mg/day for ≥30 days) in 2012. In the following 12 months, we examined: 1) annual proportion of days covered (PDC)≥0.80 and 2) presence of a≥90 day continuous gap at varying dosage thresholds: the initial >1000 mg/day, >800 mg/day, >500 mg/day, or >0 mg/day. Results:We identified 9,405 patients with advanced PD (mean age 77.4 [SD 6.8] years; 53%men). Only 5%maintained a regimen of >1000 mg/day at PDC ≥0.80; 75%had a≥90-day gap in that dosage level. At a dosage threshold of >800 mg/day, 20%had a PDC ≥0.80 and 53%had a≥90-day gap; at >500 mg/day, 56%had a PDC ≥0.80 and 19%had a≥90-day gap; and at >0 mg/day (any dose), 76%had a PDC ≥0.80 and only 10%had a≥90-day gap. Conclusion:Few patients with advanced PD sustained a high-dose oral medication regimen in the year following initiation, but most sustained a substantially lower-dose regimen. Strategies to improve advanced PD treatment are needed.