Abstract
Introduction Mild cognitive impairment is common in Parkinson's disease, even in the early stages, and can be a risk for developing dementia. To properly track development and progression of cognitive impairment, reliable measurement tools are necessary. The Montreal Cognitive Assessment is currently used as a global cognitive screening tool and has been recommended as an abbreviated diagnostic tool to measure mild cognitive impairment in the context of global cognitive function. However psychometric properties of the Montreal Cognitive Assessment in PD have not been assessed in this context. Methods Data were obtained from the Parkinson's Progression Markers Initiative (n = 395). We examine psychometric properties of the Montreal Cognitive Assessment among newly diagnosed Parkinson's disease patients using Rasch analysis. Results Only one item misfit the measurement model and principle component analysis indicated the Montreal Cognitive Assessment was unidimensional. Distribution of items calibrations formed a logical hierarchy from least to most challenging. Test items were markedly off-target (i.e., too easy) for this sample; this was also reflected in low person separation reliability. While 37% of participants performed all items correctly indicating a large ceiling effect, 22% of participants obtained a raw score in the range of 21–25 indicating mild cognitive impairment. No meaningful differential item functioning was detected. Conclusion Results suggest that in the context of early stage Parkinson's disease, the Montreal Cognitive Assessment is a unidimensional measure of global cognitive function. Implications for the use of the Montreal Cognitive Assessment in early stage Parkinson's disease and potential improvements to the assessment are discussed.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 58-64 |
| Number of pages | 7 |
| Journal | Parkinsonism and Related Disorders |
| Volume | 37 |
| DOIs | |
| State | Published - Apr 1 2017 |
Funding
PPMI, a public-private partnership, is funded by the Michael J. Fox Foundation for Parkinson's Research and funding partners, including AbbVie, Avid Radiopharmaceuticals, Biogen Idec, Bristol-Meyers Squibb, Covance, GE Healthcare, Genentech, GlaxoSmithKline, Eli Lilly and Company, Lundbeck, Merck, Meso Scale Discovery, Pfizer Inc., Piramal Imaging, Roche CNS group, Servier, UCB and Golub Capital This manuscript was also supported by a VA RR&D Career Development Award #RX001850-01. This material is also the result of work supported with resources by VA, Rehabilitation Research and Development Service, Health Services Research and Development Service and the Office of Academic Affiliations (TPH 42-012) at Edward Hines VA Hospital. Any opinions contained in this document are those of the authors and do not necessarily represent the views of the U.S. Department of Veterans Affairs or the United States Government. The authors declare that there are no conflicts of interest relevant to this work.
Keywords
- Cognition
- Montreal Cognitive Assessment
- Parkinson's disease
- Psychometrics
- Rasch analysis
ASJC Scopus subject areas
- Geriatrics and Gerontology
- Clinical Neurology
- Neurology