Observed versus Predicted Conversion from Amnestic MCI to AD over 3 Years by Brief Clinical Index Point Score.

The solid line shows the proportion of subjects predicted to progress from amnestic mild cognitive impairment (MCI) to probable Alzheimer's disease (AD) over three years as function of their brief clinical index point score, while the dotted line shows the actual proportions that progressed at each point score value based on three-year Kaplan-Meier (KM) estimates. The vertical bars show the number of individuals at each point score value (right vertical axis).