Responsiveness
Finally, responsiveness (i.e., the ability of an instrument to measure any degree of change when a known change in the concept of interest has occurred) was assessed using specific anchor measures to define groups of patients showing a change from baseline to month 36 based on the anchor measures. Specifically, patients were classified as 'improved,' 'no change,' and 'worsened' based on their change scores on 1) GDS; 2) CDR-SB; 3) global CDR, and 4) CDR-SB functional domain score. For example, patients who had a ≥ -1 point decrease on the GDS between baseline and month 36 were classified as 'improved.' Patients who had a ≥ 1 point increase on the GDS between baseline and month 36 were classified as 'worsened.' Stable patients were defined as those who did not experience any change in their condition according to the GDS between baseline and month 36 (i.e., 0 point change on the GDS).Mean change between baseline and month 36 and effect size (ES) (i.e., mean change divided by baseline standard deviation) were calculated for the ADCS-ADL-MCI total score within each change category, and effect sizes were compared [