Objective: To assess the face and content validity of the International Parkinson and Movement Disorder Society Parkinson’s Disease Psychosis Rating Scale (MDS-PDPRS), a new under-developing Clinical Outcome Assessment (COA) for Parkinson’s disease psychosis (PDP).
Background: There is no validated COA designed to assess PDP functional impact(1). The MDS-PDPRS is a clinician-reported outcome assessment to evaluate PDP severity and its effect on daily activities(2). The proposed COA includes a 5-item Diagnostic Screening Questionnaire to identify PDP, and a 2-part inventory with 14 Likert-type questions: Part 1. PDP Severity (6 items) and Part 2. Functional Impact (8 items).
Method: International, multicenter study involving up to 75 native English-speaking participants, including 30 patient-care partner dyads and 15 movement disorder specialists from the United States (USA), Australia (AUS), Canada (CAN), Nigeria (NGA), and the United Kingdom (GBR). Cognitive interviews (CI) were conducted to assess scale’s clarity, relevance, and comfort for participants divided into 3 groups and interviewed via audio-video platforms: 1) Movement Disorder Specialists: Evaluated and rated the entire MDS-PDPRS. 2) PDP Patients and Care Partners: Evaluated the Diagnostic Screening Questionnaire and all items through Part 2. 3) PD Patients without psychosis and Care Partners: Evaluated only the Diagnostic Screening Questionnaire. Cognitive screening was performed using the Montreal Cognitive Assessment (MOCA) Version 8.1 BLIND (normal score of ≥19/22).
Results: From August to December 2024, 13 participants from the USA, AUS, and NGA participated in the first round of CI. Age ranged from 62-75 (median=69) in patients (n=5), and from 50-74 (median=74) in care partners (n=5). Disease duration ranged from 1-4 years (median=1) in PD patients (n=3), 5 years for both PDP patients. MOCA scores ranged from 17-22 (median=21) in PD patients and 21-22 in care partners. Recommended refinements include clarifying medical terminology and improving transition instructions and wording. Key modifications include symptom recall timeframe, response option accuracy, and item relevance.
Conclusion: These findings offer valuable insights for further enhancing the clarity, relevance, and meaningfulness of the MDS-PDPRS items when assessing PDP severity and its functional impact.
References: 1. Mangone G, Tosin MHS, Goetz CG, Stebbins GT, Mestre TA. Unveiling Assessment Gaps in Parkinson’s Disease Psychosis: A Scoping Review. Mov Disord. 2024. Epub ahead of print. PMID: 38291860.
2. Tosin MHS, Mestre TA, Stebbins GT, Mangone G, Videmsky S, Ali S, Aarsland D, Goldman J, Khoo T, Lewis S, Martinez-Martin P, Ojo O, Pagonabarraga J, Schrag A, Weintraub D, Goetz CG. Conceptualization of the MDS Parkinson’s Disease Psychosis Rating Scale (MDS-PDPRS) prototype. [abstract]. Mov Disord. 2024; 39 (suppl 1).
To cite this abstract in AMA style:
M. Tosin, T. Mestre, G. Stebbins, G. Mangone, S. Videmsky, S. Ali, D. Aarsland, J. Goldman, T. Khoo, S. Lewis, P. Martinez-Martin, O. Ojo, J. Pagonabarraga, A. Schrag, D. Weintraub, C. Goetz. Refining the International Parkinson and Movement Disorder Society Parkinson’s Disease Psychosis Rating Scale (MDS-PDPRS): Cognitive Interview Results from an International Study [abstract]. Mov Disord. 2025; 40 (suppl 1). https://www.mdsabstracts.org/abstract/refining-the-international-parkinson-and-movement-disorder-society-parkinsons-disease-psychosis-rating-scale-mds-pdprs-cognitive-interview-results-from-an-international-study/. Accessed October 5, 2025.« Back to 2025 International Congress
MDS Abstracts - https://www.mdsabstracts.org/abstract/refining-the-international-parkinson-and-movement-disorder-society-parkinsons-disease-psychosis-rating-scale-mds-pdprs-cognitive-interview-results-from-an-international-study/