The Penn Parkinson's Daily Activities Questionnaire-15: Psychometric properties of a brief assessment of cognitive instrumental activities of daily living in Parkinson's disease

Introduction: To describe the psychometric properties of the Penn Parkinson's Daily Activities Questionnaire-15 (PDAQ-15), a 15-item measure of cognitive instrumental activities of daily living for Parkinson's disease (PD) patients derived from the original 50-item PDAQ. Methods: PDAQ-15 items were chosen by expert consensus. Knowledgeable informants of PD participants (n-= 161) completed the PDAQ-15. Knowledgeable informants were defined as an individual having regular contact with the PD participant. PD participants were assigned a diagnosis of normal cognition, mild cognitive impairment, or dementia based on expert consensus. Results: PDAQ-15 scores correlated strongly with global cognition (Dementia Rating Scale-2, r = 0.71, p < 0.001) and a performance-based functional measure (Direct Assessment of Functional Status, r = 0.83; p < 0.001). PDAQ-15 scores accurately discriminated between non-demented PD participants (normal cognition/mild cognitive impairment) and PD with dementia (ROC curve area = 0.91), participants with and without any cognitive impairment (normal cognition versus mild cognitive impairment/dementia, ROC curve area = 0.85) and between participants with mild cognitive impairment and dementia (ROC curve area = 0.84). Conclusions: The PDAQ-15 shows good discriminant validity across cognitive stages, correlates highly with global cognitive performance, and appears suitable to assess daily cognitive functioning in PD. (C) 2016 Elsevier Ltd. All rights reserved.