Development and validation of a composite score as an easy-to-use instrument for clinical monitoring of dementia progression: the composite cognitive and activities of daily living functioning score.

摘要

To the Editor: Several outcome measures can be used to describe and monitor the progression of disease severity in cognitive disorders, and several instruments are available. Research questions and available data often determine the choice of such instruments. There are specific instruments to measure cognition (global scales such as Mini-Mental State Examination (MMSE) or more-extensive neuropsy-chological assessment batteries), functional abilities (e.g., Katz activities of daily living (ADL) ), behavior (e.g., Neuropsychiatric Inventory ), and quality of life (e.g., Quality of Life in Alzheimer's Disease ), but each instrument measures just one aspect, whereas all of them are relevant to a person with cognitive impairment. Therefore, instruments combining all of these aspects, such as the Clinical Dementia Rating (CDR) scale and the Global Deterioration Scale (GDS), are usually based on clinical judgment. In spite of the validity of these composite measures, the need for clinical expertise to judge each subject can limit their use in the setting of large population-based studies because of time and financial constraints. In addition, some instruments have only a limited scale range (e.g., the GDS has 7 stages), which makes them less suitable for tracking small changes over time. Therefore, in the Kungsholmen Project (KP) -a longitudinal, population-based study on aging and dementia that followed 1,810 persons aged 75 and older for up to 12 years-an alternative composite score combining the MMSE and Katz ADL scores was developed and validated against the CDR scale.