Alternative calculation of the global clinical dementia rating

The Clinical Dementia Rating (CDR) is a widely used instrument for rating the global severity of dementia, with scores in six independently rated categories used as a basis for computing a global score. We have found that the algorithms currently used to calculate the global score from the six component scores produce results that are sometimes inconsistent with the goals of the rating scale. We systematically analyzed these incongruities and developed an alternative algorithm that eliminates them while retaining the fundamental features of the original method.