SCOPA-Cognition Cutoff Value for Detection of Parkinson’s Disease Dementia Dagmar Verbaan, PhD, 1 * Martine Jeukens-Visser, PhD, 2 Teus Van Laar, MD, PhD, 3 Stephanie M. van Rooden, MSc, 4 Erik W. Van Zwet, PhD, 5 Johan Marinus, PhD, 1 and Jacobus J. van Hilten, MD, PhD 1 1 Department of Neurology, Leiden University Medical Center, Leiden, The Netherlands 2 Department of Rehabilitation, Academic Medical Center, Amsterdam, The Netherlands 3 Department of Neurology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands 4 Department of Gerontology and Geriatrics, Leiden University Medical Center, Leiden, The Netherlands 5 Department of Medical Statistics and Bioinformatics, Leiden University Medical Center, Leiden, The Netherlands ABSTRACT: The SCOPA-Cognition is a reliable and valid test to evaluate cognitive functioning in Par- kinson’s disease and is widely used in clinical and research settings. Recently, the Movement Disorder Society introduced criteria for Parkinson’s disease dementia. The objective of the present study was to use these criteria to determine SCOPA-Cognition cut- offs for maximum accuracy, screening, and diagnosing of Parkinson’s disease dementia. A total of 282 patients with Parkinson’s disease were assessed with the SCOPA-Cognition and the Movement Disorder Society’s Parkinson’s disease dementia criteria. From the 275 patients with a complete assessment of the dementia criteria, 12% (n 5 32) fulfilled the criteria. Data from 268 patients with complete assessments of both the dementia criteria and the SCOPA-Cognition were used to determine cutoffs for maximum accuracy, screening, and diagnosing of Parkinson’s disease dementia. The area under the curve was 0.91 (95% confidence interval, 0.85–0.97), showing a strong asso- ciation between the dementia criteria and the SCOPA- Cognition. The cutoff for maximum accuracy was 22/ 23, based on the highest sum of sensitivity (0.80) and specificity (0.87), with positive and negative predictive values of 0.43 and 0.97, respectively. The optimal screening cutoff was 24/25, and the optimal diagnostic cutoff was 17/18. Using the recently published Parkin- son’s disease dementia criteria as a reference, the cur- rent study presents SCOPA-Cognition cutoffs for maximum accuracy, screening, and diagnosing of Par- kinson’s disease dementia. The availability of SCOPA- Cognition cutoffs for Parkinson’s disease dementia may contribute to the scale’s usefulness and promote its further use in both clinical and research settings. V C 2011 Movement Disorder Society Key Words: Parkinson’s disease dementia; cutoff value; SCOPA-Cognition; Movement Disorder Society Parkinson’s disease dementia criteria Parkinson’s disease (PD) is a complex disease affect- ing multiple domains, with cognitive impairment as one of its main components. Cognitive impairment in PD is characterized by involvement of memory, atten- tion, executive functioning, and visuospatial function- ing and may occur in the early disease stages. 1 A substantial number of PD patients develop Parkinson’s disease dementia (PDD) over time, which reduces the quality of life, 2 may require nursing home placement, 3 and reduces survival. 4 Risk factors for the develop- ment of PDD in PD are older age, more severe parkin- sonism, and mild cognitive impairment. 5 Point prevalence estimates of PDD range from 24% to 31% 6 and were established through different diagnos- tic criteria of PDD 6 because a standardized set of criteria for diagnosing PDD was lacking at that time. The Movement Disorder Society (MDS) recently intro- duced a standardized set of criteria for PDD (MDS- ------------------------------------------------------------ *Correspondence to: Dagmar Verbaan, PhD, Department of Neurology, K5Q-92, Leiden University Medical Center, P.O. Box 9600, NL-2300 RC Leiden, The Netherlands; D.Verbaan@lumc.nl Funding agencies: This work was supported by grants from Novartis, the Prinses Beatrix Fonds (PBF, project no. WAR05-0120), the van Alkemade-Keuls Foundation, and the Dutch Parkinson’s Disease Society. Relevant conflicts of interest/financial disclosures: Nothing to report. Full financial disclosures and author roles may be found in the online version of this article. Received: 4 November 2010; Revised: 14 March 2011; Accepted: 15 March 2011 Published online 3 May 2011 in Wiley Online Library (wileyonlinelibrary.com). DOI: 10.1002/mds.23750 RESEARCH ARTICLE Movement Disorders, Vol. 26, No. 10, 2011 1881