Covariates that significantly predicted reliably diagnosed LTH-AD in the bivariate analyses were used to create an “index of caseness” of AD according to the procedure formulated by Rice and colleagues (1992). We divided each continuous variable by its maximum value, creating values from 0 to 1, and constructed the index of caseness by averaging all the covariates bivariately predicting reliably diagnosed LTH-AD. A person having the maximum score on this variable would have the maximum value on all significant predictors of reliably diagnosed AD.
