Validation of the Japanese version of the Parkinson's Disease Questionnaire

The PDQ-39 (Parkinson's Disease Questionaire-39) is a specific quality-of-life (QOL) scale for patients with Parkinson's disease (PD). It evaluates the dysfunction of daily living and quality of life, We developed the Japanese-translated version of PDQ-39 and examined the validity of the PDQ-39 in Japanese PD patients. Subjects: A total of 156 patients with PD were studied (age 35-86 years, Hoehn-Yahr stage 1 to 4). None of the patients had dementia. Methods: Semi-structured interviews were conducted by one trained interviewer. The PDQ-39, SF-36 (36-item short form of the Medical Outcome Study questionnaire), EQ5D (Euro Qol), and NAS-J (Nottingham Adjustment Scale Japanese version) were used for evaluation. The attending physician of each patient rated the patient's condition by using the UPDRS (Unified Parkinson's Disease Rating Scale). Results: Exploratory factor analysis, Cronbach α, and construct validity were fair. and there were significant correlations between the results of the PDQ-39 and the corresponding parts of the UPDRS and SF-36, and the Hoehn-Yahr stage, respectively. Conclusion: The Japanese version of the PDQ-39 is valuable for evaluating the QOL of Japanese patients with PD. Results of comparison of PDQ-39 with other scales of the QOL such as NAS-J suggest the possibility that acceptance of the disease and feelings of self-achievement improve the QOL of patients with Parkinson's disease.