Article Document Academic Article Information Content Entity Continuant Continuant Journal Article Entity Entity Generically Dependent Continuant 2025-05-06T12:48:59 RDF description of Selection of normative group affects rates of mild cognitive impairment in Parkinson's disease - http://repository.healthpartners.com/individual/document-rn7457 Selection of normative group affects rates of mild cognitive impairment in Parkinson's disease 10.1002/mds.27335 Movement Disorders 5 Dementia 33 13672 21924 <p>OBJECTIVE: The objective of this study was to examine the impact of different methods of standardizing cognitive data in the Parkinson's Progression Marker Initiative. METHODS: Cognitive data from 423 participants with Parkinson's disease were included (age = 61.7 [9.7], education = 15.6 [3.0]). Internal norms were calculated using the group mean and standard deviation of the healthy control group. Published norms were compared to the overall group mean of and to age-stratified norms from healthy controls for each neuropsychological test over 4 visits. Rates of mild cognitive impairment were calculated using established criteria. RESULTS: The use of internal norms resulted in lower standardized scores than published norms on all tests with the exception of memory and processing speed (P </= .001). Individuals were 1.5 to 2.1 times more likely to be diagnosed with mild cognitive impairment using internal norms than published norms. CONCLUSIONS: Standardization approaches with cognitive data are not interchangeable. Selection of a normative comparison group impacts research and clinical interpretations of cognitive data.<p> Parkinson Disease 2022-02-21T22:48:57.408-06:00 public Follow-Up Studies document-rn7457