Uncovering Indicators of the International Classification of Functioning, Disability, and Health from the 39-Item Parkinson's Disease Questionnaire
Figure 1
Category probability curves depicting the probability (y-axis) of observing responses in each category (0 = never; 1 = seldom; 2 = sometimes; 3 = often; 4 = always) relative to the location on the measured construct (x-axis; positive values = more problems) for item 28 before (a) and after (b) rescoring. This item was associated with multiple disordering (thresholds 0-to-1/1-to-2 and thresholds 2-to-3/3-to-4) and needed reduction from five to three response categories (combination of responses to categories 1, 2, and 3 into a single category).
