“…However, because cognitive effects are secondary to biological changes in the brain, an appropriate biological test might more accurately reflect the disease process. Much recent work seeks to make AD diagnoses or predictions based on biological markers (Convit, de Asis, de Leon, Tarshish, De Santi, & Rusinek, 2000; Visser, Verhey, Hofman, Scheltens, & Jolles, 2002; Devanand, et al, 2008; Walhovd, et al, 2010; Clark & ADNI, 2011; Cui, et al, 2011; Furney, et al, 2011; Palmqvist, et al, 2012; Ye, et al, 2012; Zhang, Shen, & ADNI, 2012). Among the studies cited here that incorporate biological tests, those that include some form of cross-validation or a separate test set report accuracies ranging from 62% to 85%.…”