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Development of Clinical Dementia Rating Scale Cut‐off Scores for Patients With Parkinson's Disease
Author(s) -
WymanChick Kathryn A.,
Scott BJ
Publication year - 2015
Publication title -
movement disorders clinical practice
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.754
H-Index - 18
ISSN - 2330-1619
DOI - 10.1002/mdc3.12163
Subject(s) - dementia , clinical dementia rating , receiver operating characteristic , rating scale , confidence interval , medicine , area under the curve , parkinson's disease , disease , cognitive impairment , cognition , psychology , psychiatry , developmental psychology
Abstract Background The aim of this study was to explore validity of the Clinical Dementia Rating Scale (CDR) in measuring cognitive impairment among individuals with Parkinson's disease (PD). The scale was created for use in patients with Alzheimer's disease, and, to date, there have been no published studies examining whether this tool is appropriate for patients with PD. Methods The data were obtained from the National Alzheimer's Coordinating Center database and included 490 subjects diagnosed with PD, further categorized as having PD dementia (n = 151), mild cognitive impairment (n = 186), or normal cognition (n = 153) by a treating physician. Sensitivity, specificity, positive predictive value, and negative predictive value were calculated for the CDR Scale Global Score as well as the Sum of Boxes Score using existing cut‐off scores. Finally, new cut‐off scores were calculated using sensitivity and specificity values derived using receiver operating characteristic curves. Results Sensitivity and specificity of the published Global Score cut‐off scores for patients with dementia were 0.34 and 0.10, respectively. The newly calculated cut‐off scores for patients with dementia yielded a sensitivity of 0.79 and a specificity of 0.96. The area under the curve was 0.92 (95% confidence interval = 0.90–0.95). Conclusion The CDR is a useful tool in identifying dementia in patients with PD when the cut‐off scores are adjusted.