Patients' Preferences for Adjunctive Parkinson's Disease Treatments: A Discrete-Choice Experiment.

Background: Several adjunctive medications are available to reduce OFF time between levodopa/carbidopa (LD/CD) doses for people with Parkinson's disease (PD).
Objective: To explore how individuals with PD balance benefits and burdens when considering adjunctive medications.
Methods: US adults (30-83 years) with self-reported PD, currently treated with LD/CD, who experienced OFF episodes were recruited through the Fox Insight study to complete a discrete-choice experiment survey. Respondents selected among experimentally designed profiles for hypothetical adjunctive PD treatments that varied in efficacy (additional ON time), potential adverse effects (troublesome dyskinesia, risk of diarrhea, risk of change in bodily fluid color), and dosing frequency or the option "No additional medicine". Data were analyzed with random-parameters logit models.
Results: Respondents (N=480) would require ≥60 additional minutes of daily ON time to accept either a 40% risk of change in bodily fluid color or 10 additional minutes with troublesome dyskinesia daily. Respondents would require 40 additional minutes of daily ON time to accept a 10% risk of diarrhea and 22 additional minutes of daily ON time to switch from 1 additional pill each day to 1 pill with each LD/CD dose. On average, respondents preferred adjunctive PD medication over no additional medication. Results predicted that 59.1% of respondents would select a hypothetical treatment profile similar to opicapone, followed by no additional medication (27.5%) and a hypothetical treatment profile similar to entacapone (13.4%).
Limitations: The data collected were based on responses to hypothetical choice profiles in the survey questions. The attributes and levels selected for this study were intended to reflect the characteristics of opicapone and entacapone; attributes associated with other adjunctive therapies were not evaluated.
Conclusion: Patients with PD expressed interest in adjunctive treatment to increase ON time and would accept reduced ON time to avoid adverse effects.
Competing Interests: Michael Serbin, Charles Yonan, and Olga Klepitskaya are employees of Neurocrine Biosciences. Carol Mansfield is an employee of RTI Health Solutions, and Colton Leach was an employee of RTI Health Solutions when this research was conducted. Connie Marras is on the steering committee for the Fox Insight study. Margaret Sheehan and Anne Donnelly have nothing to disclose for this work.
(© 2023 Serbin et al.)