Tree-Based Classification of AD Risk Using KappaTree Lead Investigator: Jeannie-Marie Leoutsakos Institution : Johns Hopkins School of Medicine E-Mail : jeannie-marie@jhu.edu Proposal ID : 310 Proposal Description: We propose to use a specific tree-based machine learning algorithm (Kappatree Petras et al, 2013), to find optimal combinations of baseline predictors of AD conversion among non-demented individuals. Kappatree allows for differential weighting of sensitivity and specificity we will compare prediction algorithms when they are equally weighted (which will maximize classification accuracy), when sensitivity is maximized (for screening purposes) and when specificity is maximized (for the purpose of identifying individuals to enroll in prevention trials).