{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,29]],"date-time":"2026-04-29T19:17:05Z","timestamp":1777490225360,"version":"3.51.4"},"reference-count":17,"publisher":"MDPI AG","issue":"7","license":[{"start":{"date-parts":[[2026,3,31]],"date-time":"2026-03-31T00:00:00Z","timestamp":1774915200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"individuals and families impacted by Parkinson\u2019s disease"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Nutrients"],"abstract":"<jats:p>Background: The Patient\u2013Reported Outcomes in Parkinson\u2019s Disease (PRO-PD) scale is a 35-item visual analog measure designed to quantify symptom severity across motor and non-motor domains. Developed as a continuous, patient-centered outcome, PRO-PD captures patient-perceived change over time and is suitable for remote longitudinal assessment. This study evaluated the psychometric properties of PRO-PD across two independent datasets, including reliability, validity, factor structure, and minimal clinically important difference (MCID), and assessed its relevance to nutrition- and lifestyle-focused research. Methods: Convergent validity was evaluated in a cross-sectional clinical dataset (n = 46) using established clinician-rated and patient\u2013reported instruments, including Hoehn and Yahr, Unified Parkinson\u2019s Disease Rating Scale (UPDRS), Parkinson\u2019s Disease Questionnaire-39 (PDQ-39), Montreal Cognitive Assessment (MoCA), and PROMIS measures. Internal consistency, temporal stability, factor structure, and known-groups validity were assessed in a large remote-monitoring cohort (n = 2612). MCID thresholds were estimated in a longitudinal subsample (n = 390) using anchor-based methods, multinomial regression, and receiver operating characteristic analyses. Results: PRO-PD demonstrated strong convergent validity with established clinical measures, excellent internal consistency (Cronbach\u2019s \u03b1 = 0.93 (95% CI: 0.90\u20130.96) for Small Data and 0.95 (95% CI: 0.947\u20130.951) for Big Data\u201d), and good test\u2013retest reliability (ICC = 0.78 overall; 0.89 at 6 months). Confirmatory testing of a previously proposed eight-factor structure showed suboptimal fit, leading to a parsimonious four-factor solution (Neurobehavioral, Autonomic, Motor, Mood\/Motivation) explaining 47.6% of variance. PRO-PD scores increased significantly with advancing disease duration and stage. MCID thresholds were +53.5 points for worsening and \u221278.5 points for improvement (AUC = 0.64 for worsened vs. not worsened; AUC = 0.71 for improved vs. worsened), with greater sensitivity for detecting deterioration than improvement. PRO-PD scores demonstrated sensitivity to patient-perceived symptom change over time, supporting its utility for longitudinal monitoring and potential application in lifestyle-focused intervention research. Conclusions: These findings support PRO-PD as a psychometrically robust outcome measure that can be completed remotely without trained administrators.<\/jats:p>","DOI":"10.3390\/nu18071118","type":"journal-article","created":{"date-parts":[[2026,3,31]],"date-time":"2026-03-31T13:23:17Z","timestamp":1774963397000},"page":"1118","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":1,"title":["Validation of a Patient\u2013Reported Outcome Measure in Parkinson\u2019s Disease"],"prefix":"10.3390","volume":"18","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-1166-6978","authenticated-orcid":false,"given":"Laurie K.","family":"Mischley","sequence":"first","affiliation":[{"name":"Research Institute, School of Naturopathic Medicine, Bastyr University, Kenmore, WA 98028, USA"},{"name":"Department of Radiology (Research), School of Medicine, University of Washington, Seattle, WA 98109, USA"},{"name":"Parkinson Center for Pragmatic Research, Seattle, WA 98133, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9777-2899","authenticated-orcid":false,"given":"Magdalena","family":"Murawska","sequence":"additional","affiliation":[{"name":"Parkinson Center for Pragmatic Research, Seattle, WA 98133, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2026,3,31]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Luo, Y., Qiao, L., Li, M., Wen, X., Zhang, W., and Li, X. (2024). Global, regional, national epidemiology and trends of Parkinson\u2019s disease from 1990 to 2021: Findings from the Global Burden of Disease Study 2021. Front. Aging Neurosci., 16.","DOI":"10.3389\/fnagi.2024.1498756"},{"key":"ref_2","unstructured":"GBD 2015 Neurological Disorders Collaborator Group (2017). Global, regional, and national burden of neurological disorders during 1990\u20132015: A systematic analysis for the Global Burden of Disease Study 2015. Lancet Neurol., 16, 877\u2013897."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"15","DOI":"10.1038\/s41531-020-0117-1","article-title":"Current and projected future economic burden of Parkinson\u2019s disease in the U.S","volume":"6","author":"Yang","year":"2020","journal-title":"npj Park. Dis."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"442","DOI":"10.1056\/NEJMra2401857","article-title":"Parkinson\u2019s Disease","volume":"391","author":"Tanner","year":"2024","journal-title":"N. Engl. J. Med."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"2129","DOI":"10.1002\/mds.22340","article-title":"Movement Disorder Society-sponsored revision of the Unified Parkinson\u2019s Disease Rating Scale (MDS-UPDRS): Scale presentation and clinimetric testing results","volume":"23","author":"Goetz","year":"2008","journal-title":"Mov. Disord."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"2034","DOI":"10.1002\/mdc3.70231","article-title":"Opicapone in Parkinson\u2019s Disease on Levodopa-Carbidopa Intestinal Gel Treatment: A Pilot, Randomized Study","volume":"12","author":"Colucci","year":"2025","journal-title":"Mov. Disord. Clin. Pract."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"e00728","DOI":"10.1016\/j.neurot.2025.e00728","article-title":"A double-blind, controlled trial of circadian effective light therapy in patients with Parkinson\u2019s disease","volume":"22","author":"Wyman","year":"2025","journal-title":"Neurotherapeutics"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"7036","DOI":"10.1016\/j.cell.2025.09.010","article-title":"Phase 1\/2a clinical trial of hESC-derived dopamine progenitors in Parkinson\u2019s disease","volume":"188","author":"Chang","year":"2025","journal-title":"Cell"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"1927","DOI":"10.1007\/s00415-019-09348-3","article-title":"Does the MDS-UPDRS provide the precision to assess progression in early Parkinson\u2019s disease? Learnings from the Parkinson\u2019s progression marker initiative cohort","volume":"266","author":"Regnault","year":"2019","journal-title":"J. Neurol."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"101","DOI":"10.1038\/s41531-024-00716-z","article-title":"Patient-centered development of clinical outcome assessments in early Parkinson disease: Key priorities and advances","volume":"10","author":"Mestre","year":"2024","journal-title":"npj Park. Dis."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"S47","DOI":"10.1016\/j.parkreldis.2017.07.029","article-title":"Historical perspective: The pros and cons of conventional outcome measures in Parkinson\u2019s disease","volume":"46","author":"Lim","year":"2018","journal-title":"Park. Relat. Disord."},{"key":"ref_12","doi-asserted-by":"crossref","unstructured":"AlMahadin, G., Lotfi, A., Zysk, E., Siena, F.L., Carthy, M.M., and Breedon, P. (2020). Parkinson\u2019s disease: Current assessment methods and wearable devices for evaluation of movement disorder motor symptoms\u2014A patient and healthcare professional perspective. BMC Neurol., 20.","DOI":"10.1186\/s12883-020-01996-7"},{"key":"ref_13","unstructured":"Center for Drug Evaluation and Research, Center for Biologics Evaluation and Research, and Center for Devices and Radiological Health (2023). Patient-Focused Drug Development: Incorporating Clinical Outcome Assessments into Endpoints for Regulatory Decision-Making."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"20","DOI":"10.1038\/s41531-017-0021-5","article-title":"Use of a self-rating scale of the nature and severity of symptoms in Parkinson\u2019s Disease (PRO-PD): Correlation with quality of life and existing scales of disease severity","volume":"3","author":"Mischley","year":"2017","journal-title":"npj Park. Dis."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"1668","DOI":"10.1002\/mds.29517","article-title":"Validation of the Swedish Patient-Reported Outcomes in Parkinson\u2019s Disease Scale in Outpatients","volume":"38","author":"Wallerstedt","year":"2023","journal-title":"Mov. Disord."},{"key":"ref_16","first-page":"289","article-title":"Phase IIb Study of Intranasal Glutathione in Parkinson\u2019s Disease","volume":"7","author":"Mischley","year":"2017","journal-title":"J. Park. Dis."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"14","DOI":"10.1177\/08919887251346495","article-title":"Physical Activity, Patient-Reported Outcomes, and Quality of Life in Parkinson\u2019s Disease","volume":"39","author":"Morley","year":"2026","journal-title":"J. Geriatr. Psychiatry Neurol."}],"container-title":["Nutrients"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2072-6643\/18\/7\/1118\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,3,31]],"date-time":"2026-03-31T13:37:55Z","timestamp":1774964275000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2072-6643\/18\/7\/1118"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,3,31]]},"references-count":17,"journal-issue":{"issue":"7","published-online":{"date-parts":[[2026,4]]}},"alternative-id":["nu18071118"],"URL":"https:\/\/doi.org\/10.3390\/nu18071118","relation":{},"ISSN":["2072-6643"],"issn-type":[{"value":"2072-6643","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,3,31]]}}}