Comparative Effectiveness of Carbidopa/Levodopa Enteral Suspension and Deep Brain Stimulation on Pill Burden Reduction in Medicare Fee-for-Service Patients with Advanced Parkinson's Disease

Neurol Ther. 2023 Apr;12(2):459-478. doi: 10.1007/s40120-022-00433-w. Epub 2023 Jan 18.

Abstract

Introduction: Complex polypharmacy regimens to manage persistent motor fluctuations result in significant pill burden for patients with advanced Parkinson's disease (APD). This study evaluated the effectiveness of carbidopa/levodopa enteral suspension (CLES) and deep brain stimulation (DBS) on reducing pill burden in APD patients.

Methods: We utilized 100% Medicare fee-for-service claims from 2014 to 2018 linked to CLES Patient Support Program (PSP) data. CLES initiators (CLES-I) were propensity matched 1:1 with patients enrolled in PSP who did not initiate treatment (CLES-NI) (N = 188) or undergo DBS, and 1:3 with patients who received DBS (N = 204, N = 612). Average daily pill burden and levodopa equivalent daily dosage (LEDD) were measured at baseline, 0-6 months and 7-12 months follow-up.

Results: CLES-I and CLES-NI had higher pill burden than DBS patients at baseline. However, at 6 months post-treatment, CLES-I had significantly fewer pills/day than CLES-NI (4.7 versus 11.4, p < 0.05) and DBS (4.8 versus 7.4, p < 0.05). A significant reduction in pill burden was observed at 0-6 months (46.3%) and 7-12 months (68.3%) follow-up for CLES-I (p < 0.001) versus increased burden for CLES-NI (+10.5%, p < 0.05 and +8.2%, p > 0.05) and insignificant reductions for DBS (-3.9% and -6.1%, p > 0.05). Mean adjusted pill burden showed 57.3% fewer pills at 0-6 months and 74.1% at 7-12 months among CLES-I compared with CLES-NI, and 49.6% and 70.1% reduction compared with DBS. CLES-I showed a decrease in LEDD at 7-12 months compared with baseline (935 to 237 mg) and to CLES-NI (237 mg versus 1112 mg) and DBS patients (236 mg versus 594 mg).

Conclusion: CLES led to a significant reduction in pill burden and oral LEDD compared with CLES-NI and DBS patients. Pill burden reduction could be considered a treatment goal for patients with APD challenged by complex polypharmacy regimens that interfere with activities of daily living and quality of life.

Keywords: Carbidopa; Carbidopa and levodopa enteral suspension; Deep brain stimulation; Device-aided therapy; Levodopa; Levodopa equivalent daily dose; Medicare; Parkinson’s disease; Pill burden; Real-world evidence.

Plain language summary

Management of uncontrollable motor movements in patients with advanced Parkinson’s disease rely on oral levodopa-based treatments. Non-motor symptoms such as depression and anxiety are managed with additional oral medications. Over time, higher and more frequent dosing of oral medications is required, resulting in complex medication regimens that impact quality of life and adherence.A real-world study of 10,752 Parkinson’s disease patients between 2014 and 2018 evaluated the effectiveness of two device-aided therapies to reduce pill burden, carbidopa/levodopa enteral suspension and deep brain stimulation. Carbidopa/levodopa suspension treatment involves continuous delivery of levodopa to the intestines through a surgical port attached to a portable pump. Brain stimulation involves surgery to attach metal wires to the brain to send electrical pulses via an implanted stimulator.As Parkinson’s disease predominately affects the elderly, we compared Medicare patients on carbidopa/levodopa suspension to a matched control group receiving no suspension and to those receiving brain stimulation. Average pill burden/day was measured prior to receiving a device-aided treatment (baseline) and at 0–6 months and 7–12 months post-treatment (follow-up).The top graph shows that by 6-months post-treatment, patients on carbidopa/levodopa suspension required fewer pills than those without suspension (4.7 versus 11.4), with further pill reduction at 12 months (3.5 versus 11.1). The bottom graph shows that by 6 months, patients on carbidopa/levodopa suspension required fewer pills than patients treated with brain stimulation (4.8 versus 7.4), with further reduction at 12 months (3.6 versus 7.0). The reduction in oral pill burden suggests that the carbidopa/levodopa suspension may present an opportunity to simplify treatment regimens.