Validity and reliability testing of the Chinese （mainland） version of the 39-item Parkinson＇s Disease Questionnaire （PDQ-39）

The 39-item Parkinson＇s Disease Questionnaire （PDQ-39） has been tested in many languages, but not in Chinese mainland. We aimed to assess the Chinese （mainland） version of the PDQ-39. Seventy-one subjects with Parkinson＇s disease （PD） completed the PDQ-39 and the Medical Outcomes Study 36-item Short Form Health Survey （SF-36）. All subjects were retested with the PDQ-39 a week later. The united Parkinson＇s disease rating scale （UPDRS） and the Hoehn and Yahr （H ＆ Y） scale were also used to evaluate the subjects. Reliability was assessed by Cronbach＇s cr and intra-class correlation coefficient （ICC）. Validity was examined in terms of agreement with SF-36, UPDRS, and H ＆ Y scales. The Chinese （mainland） version of the PDQ-39 demonstrated acceptable reliability （Cronbach＇s a： 0.84-0.88; ICC： 0.56-0.82）. The item-total correlations （0.33-0.88） and scaling success rates （77.56%） indicated satisfactory convergent and discriminant validity of the PDQ-39 items. The correlations between related constructs of the PDQ-39 and UPDRS （r=0.44-0.68） and between those of the PDQ-39 and SF-36 （t=（-0.46）-（-0.69）） were all statistically significant （,~〈0.01）. Except for stigma, cognitions, and bodily discomfort, all other dimensions of the PDQ-39 significantly discriminated patients at different H ＆ Y stages indicated by the H ＆ Y scale. Although our observations indicate that some problematic subscales of this version of the PDQ-39 could be improved upon, this study suggests acceptable reliability and validity of the Chinese （mainland） version of the PDQ-39.