Validation of the Korean Version of the Questionnaire for Impulsive-Compulsive Disorders in Parkinson's Disease Rating Scale

Abstract

Background and purpose: Impulse-control disorder is an important nonmotor symptom of Parkinson's disease (PD) that can lead to financial and social problems, and be related to a poor quality of life. A nationwide multicenter prospective study was performed with the aim of validating the Korean Version of the Questionnaire for Impulsive-Compulsive Disorders in Parkinson's Disease Rating Scale (K-QUIP-RS).

Methods: The K-QUIP-RS was constructed using forward and backward translation, and pretesting of the prefinal version. PD patients on stable medical condition were recruited from 27 movement-disorder clinics. Participants were assessed using the K-QUIP-RS and evaluated for parkinsonian motor and nonmotor statuses and for PD-related quality of life using a predefined evaluation battery. The test-retest reliability of the K-QUIP-RS was assessed over an interval of 10-14 days, and correlations between the KQUIP-RS and other clinical scales were analyzed.

Results: This study enrolled 136 patients. The internal consistency of the K-QUIP-RS was indicated by a Cronbach's α coefficient of 0.846, as was the test-retest reliability by a Guttman split-half coefficient of 0.808. The total K-QUIP-RS score was positively correlated with the scores for depression and motivation items on the Unified PD Rating Scale (UPDRS), Montgomery-Asberg Depression Scale, and Rapid-Eye-Movement Sleep-Behavior-Disorders Questionnaire. The total K-QUIP-RS score was also correlated with the scores on part II of the UPDRS and the PD Quality of Life-39 questionnaire, and the dopaminergic medication dose.

Conclusions: The K-QUIP-RS appears to be a reliable assessment tool for impulse-control and related behavioral disturbances in the Korean PD population.

Keywords: compulsive behavior; impulsive behavior; parkinson disease; rating scale; validation study.

Fig. 1. Correlations between the total score on the K-QUIP-RS and other clinical measures. (A) total LED (R²=0.078, p=0.019) and scores on the (B) K-MADS (R²=0.033, p=0.009), (C) K-PDQ39 SI (R²=0.052, p=0.009), and (D) K-RBDQ (R²=0.057, p=0.010). K-MADS: Korean Version of the Montgomery-Asberg Depression Scale, K-PDQ39: Korean Version of the Parkinson's Disease Questionnaire-39, K-QUIP-RS: Korean Version of the Questionnaire for Impulsive-Compulsive Disorders in Parkinson's Disease Rating Scale, K-RBDQ: Korean Version of the Rapid-Eye-Movement Sleep-Behavior-Disorders Screening Questionnaire, LED: levodopa equivalent dose, SI: summary index.