The psychometric properties of the Dutch version of the Parkinson's disease 
questionnaire 39 (PDQ39-DV) were tested in 177 patients with Parkinson's disease 
(PD). Internal consistency of 7 of the 8 scales was adequate (>or=0.70), but was 
insufficient for 'bodily discomfort' (0.59). Correlation between the PDQ39 and 
other instruments in this study, the SCOPA-psychosocial questionnaire, 
Euroqol-5D, hospital anxiety and depression scale, and a visual analogue scale 
for quality of life, were 0.82, 0.74, 0.63 and -0.54, respectively. The factor 
analysis yielded 8 factors, which accounted for 65% of the variance and revealed 
only small differences with the original UK version. We conclude that the 
PDQ39-DV displays satisfactory psychometric properties and is an appropriate 
instrument to assess quality of life in Dutch patients with PD.