Greater Precision When Measuring Dementia Severity: Establishing Item Parameters for the Clinical Dementia Rating Scale

摘要

Background/AimsAn item response theory (IRT)-based scoring approach to the Clinical Dementia Rating (CDR) scale can account for the pattern of scores across the CDR items (domains) and the items’ differential abilities to indicate dementia severity. In doing so, an IRT-based approach can provide greater precision than other CDR scoring algorithms. However, neither a good set of item parameters nor an easily digestible set of instructions needed to implement this approach is readily available.