Ability to detect change of domain scores.
The ability of the PIB score (weekly mean) to detect change was evaluated by use of the PGIC anchor, while the ability of the Decision Tree score to detect change was investigated by comparison with the CGIS anchor. Subjects were divided into three groups depending on their progression from Visit 1 to Visit 2. These groups included ‘Improved’ subjects (very much improved, much improved, or a little improved at Visit 2), ‘Stable’ subjects (no change at Visit 2), and ‘Worsened’ subjects (a little worse, much worse or Very much worse at Visit 2). The mean change score was determined. One-way ANOVA F-test was used to calculate potential statistical significance of differences in change scores between groups.For the Decision Tree score, a larger negative change in mean score was shown for the improved group (mean change score = −0.4) compared to the stable one (mean change score = −0.1). Moreover, the worsened group demonstrated a positive change in mean score (mean score = 0.1) compared to the stable group (mean change score = −0.1) (