The Alzheimer's disease activities of daily living international scale (ADL-IS)

Background: Activities of daily living (ADL) deficits are integral componen ts of dementia disorders, and ADL measures are among the most robust marker s of the course of Alzheimer's disease (AD). Despite this acknowledged impo rtance, no clearly useful ADL instrument for cross-cultural application in pharmacologic trials in the early stages of AD had been available. Method: An international effort was launched to develop an ADL scale for pharmacolo gic trials in early AD. Steps taken from 1990 to the present included: (1) international scientific working group meetings and reviews, (2) reviews of existing measures, (3) collating of existent, nonredundant items, (4) quer ying experts for new items, (5) interviews with informants and subjects in the USA, France, and Germany, toward the identification of potential new it ems, (6) identification of an item pool based upon these procedures, (7) cr eation of a trial instrument, (8) piloting of this instrument, and (9) refi nement of the scale based upon statistical analysis of the pilot data. Fina l item selection was based upon: (1) relevance for greater than or equal to 80% of subjects in severity-stratified USA and German samples; (2) absence of gender and national biases; (3) significant (p < .05) discrimination be tween (a) normal versus mildly impaired and (b) mildly impaired versus mode rately to moderately severely impaired subjects; and (4) Global Deteriorati on Scale (GDS) scores accounting for greater than or equal to 12% of varian ce in the item after controlling for age and gender. Results: An ADL scale consisting of 40 items that correlate with the global and cognitive progres s of AD is developed for international usage in pharmacologic trials in inc ipient, mild, moderate, and moderately severe AD. The scale contains 40 ite ms falling within 13 ADL categories. The 40-item scale is shown to have .81 correlation with GDS staging,.81 with mental status assessment (Mini-Menta l State Examination), and .81 with a psychometric test (the SKT) (p values < .001). Conclusion: This scale can be used to measure therapeutic response in AD.