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

The PDQ-39 (Parkinson's Disease Questionnaire-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.

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.

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).

Exploratory factor analysis, Cronbach alpha, 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.

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.