The Cognition and Emotional Well-being indices of the Parkinson's disease questionnaire-39: What do they really measure?

Abstract

Introduction The Parkinson's disease questionnaire-39 (PDQ-39) is a common measure of health related quality of life (HRQoL) that is widely used with Parkinson disease (PD) patients. Previous evidence suggests that the PDQ-39 reflects at least 8 dimensions (i.e., Emotion, Cognitions, Mobility, etc). To date, little research has examined the external/convergent validity of the Cognitions and Emotional Well-being domains of the PDQ-39. Methods A convenience sample of 303 PD patients underwent a comprehensive multi-domain neuropsychological evaluation, including tests of execution function, episodic verbal memory, processing speed, language and working memory, as well as completing measures of depression, apathy, state and trait anxiety and HRQoL (PDQ-39). Hierarchical regressions were conducted in order to examine the relationship between scores on neuropsychological tests and the Cognitions index, as well as mood measures and the Emotional Well-being index of the PDQ-39. Results Neuropsychological test performance did not account for a significant amount of variance in the PDQ-39 Cognitions index scores. Instead, it was depression that significantly contributed to the Cognitions index, above and beyond neuropsychological performance. The PDQ-39 Emotional Well-being index was also related to mood measures, primarily depression and trait anxiety. Conclusions The PDQ-39 Cognition index may be more related to mood functioning, as opposed to cognitive functioning, and should not be considered a “proxy” for cognitive functioning. Future studies are needed to better explain the construct of this index.

The impact of cognitive performance on quality of life in individuals with Parkinson's disease

“…These findings corroborate evidence in the literature 22 - 26 showing that worse quality of life and depression are associated with worse cognitive performance or presence of dementia in individuals with PD. In the studies, 22 - 25 there was a significant correlation between quality of life measured by PDQ-39 or PDQ- 8 and better performance on cognitive assessments.…”

“…Regarding depression, Klepac et al (2008) 22 observed a correlation between lower scores on the BDI with better scores on cognition and quality of life. Ng et al (2015) 25 found lower scores on cognitive tests in individuals with PD and depression when compared to patients without depression and to healthy controls. Furthermore, Wang et al (2014) found that depression is a predictive risk factor for cognitive impairment in PD with an OR=1.98 and p=0.03.…”

Emotional cues from expressive behavior of women and men with Parkinson’s disease

“…Third, the Emotional Well-being subscale of the Parkinson’s Disease Questionnaire-39 items (PDQ-39) [ 37 ] measured self-reported emotional experience over the past month. The items of this subscale address attributes primarily related to depression and anxiety [ 38 ]. A higher score indicates more negative emotional experience.…”

Sicca Symptoms in Parkinson’s Disease: Association with Other Nonmotor Symptoms and Health-Related Quality of Life

“…In particular, cognition was negatively influenced by autonomic symptoms. To interpret this result, it is noteworthy that the cognition domain shows a stronger relationship to mood, especially depression, than to measure of cognitive function [19]. e cognitive domain shows some overlap with the emotional well-being domain, which is primarily influenced by symptoms of depression and long-standing anxiety.…”