The incongruities of the NPI-Q score obtained by the caregiver versus that obtained directly from the non-demented patient with Parkinson's disease

Background: Neuropsychiatric symptomatology frequently accompanies Parkinson's disease. Purpose: In this work (a one point time analytical study), we wished to explorer the Neuropsychiatric Inventory in its shorter format (NPI-Q) in seventy consecutive patients. To find out in what way information obtained from the caregiver (CG) is correlated with that which the patients provide. If this tool, designed to evaluate patients with dementia, can be applied to non-demented subjects with Parkinson's disease (NDP). Method: The study, the NPI-Q Spanish version was employed, first with the CG alone and subsequently, with the individual patient alone by a researcher with no knowledge of the previous result from the CG. The weighted kappa correlation coefficient was measured to evaluate the CG-NDP consistency rate (Test-retest reliability; obtained by judging the reproductibility or stability of a instrument over time; two or more observers; or two or more times); a value of 0.7 or higher was accepted as significant. Because the correlation results were found to be insignificant, a post-hoc analysis was performed. We study the convergent validity (Validity-Construct-related, include examining the logical relations that should exist with other measures, know too as convergent validity) analyzed using the Spearman rank correlation statistic values greater than (r <0.29 are weak correlations; r <0.3-0.58 are moderate correlations and; r < 0.59 are high correlations the convergent validity). Results: The consistency inter-rater (CG-NDP), were without any significant agreement; in the inter-items correlations the best values were for the patients; and in the Spearman's correlations (a measure of converging validity), the values obtained on the NDP were more significant. Conclusions: We can assume that the patient's NDP is the best source of information, and hence for these patients, we consider that the NPI-Q (reported by the CG) is not the best tool to evaluate the Neuropsychiatric symptomatology of NDP sufferers.