title: Quality of life and Parkinson's disease: translation and validation of the US Parkinson's Disease Questionnaire (PDQ-39).
abstract: Parkinson's disease is a common progressive neurodegenerative disorder affecting an estimated 4 million people worldwide. A number of general health status measures exist but few fully capture the subjective evaluation of life quality associated with Parkinson's disease. We report here the results of: (1) translating the British PDQ-39 into a US version, (2) validity and reliability of the new US PDQ-39 questionnaire, and (3) parallel validation analyses following the method published in the development of the British version of the PDQ-39. Data were collected by postal survey on 150 patients recruited from neurology clinics in the Seattle area. A short, generic health status measure (SF-36) was used to test convergent validity, and a three-day test-retest assessed the reliability of the PDQ-39. The US version of the PDQ-39 demonstrated acceptable internal consistency (alpha = 0.51 to 0.96) and proved to be reproducible (0.86 to 0.96). Subscales of the PDQ-39 showed convergence with like scales of the SF-36 and was able to discriminate between levels of symptom severity.
authors.affiliation: Health Research Associates, Inc., Seattle, WA, USA. hrainc@accessone.com
authors.forename: D M
authors.initials: DM
authors.lastname: Bushnell
authors.forename: M L
authors.initials: ML
authors.lastname: Martin
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003431:Cross-Cultural Comparison; D005163:Factor Analysis, Statistical; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000523:psychology*; D011594:Psychometrics; D011788:Quality of Life; D015203:Reproducibility of Results; D011795:Surveys and Questionnaires; D014175:Translating; D006113:United Kingdom; D014481:United States