title: Reliability and validity of PDQ-39: a quality-of-life measure for patients with PD in China.
abstract: The syndromes of Parkinson's disease (PD) have impacts on health-related quality of life (HRQL). The 39-item Parkinson's disease Questionnaire (PDQ-39) was the first specific and a consistent instrument for the evaluation of HRQL in PD patients.
  
  
  OBJECTIVE
  To test the reliability and validity of Chinese version PDQ-39.
  
  
  METHODS
  Hundred and twenty-six PD without cognitive impairment were enrolled. The Chinese version of SF-36 was used to evaluate the congruent validity of PDQ-39 between related domains. Both PDQ-39 and SF-36 scales were fulfilled by the patients themselves.
  
  
  RESULTS
  Five of eight subscales of PDQ-39 met the acceptable standards of reliability (Cronbach's α coefficient >0.80), while the other three subscales (cognition, communication, and bodily discomfort) failed to reach the above standards as reported by the others. All the item-to-subscale correlations (range: 0.457-0.887) met the minimal acceptable item convergent validity criterion of 0.40 (P < 0.001). Correlation between PDQ-39 subscales and scales of the SF-36 had high negative correlations with a range of -0.759 to -0.124. Four of them had significant negative correlations (P < 0.0001).
  
  
  CONCLUSIONS
  The Chinese version of PDQ-39 is a reliable and valid instrument for Chinese PD patients. It is recommended as the most appropriate HRQL tool for PD.
authors: Department of Neurology and Neurobiology, Beijing Institute of Geriatrics and Xuanwu Hospital of the Capital Medical University, #45 Changchun Street, 100053 Beijing, China. littlenumskull@hotmail.com
authors: Jing-Lin
authors: JL
authors: Zhang
authors: Piu
authors: P
authors: Chan
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002681:China; D005260:Female; D006304:Health Status; D006801:Humans; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000503:physiopathology*; D011594:Psychometrics / Q000295:instrumentation; D011788:Quality of Life; D011795:Surveys and Questionnaires / Q000592:standards; D055815:Young Adult