Validity of the extended activities of daily living scale

Abstract

Scales that measure independence in the basic self-care activities of daily living (ADLs) suffer from ceiling effects when applied to an outpatient population. The instrumental activities of daily living (IADL) measures, which assess the performance of tasks required for independence at home are more appropriate. However, validity evaluation of IADL measures seldom goes beyond content validity and little is known about their sensitivity to change. The aim of this study was to evaluate the construct validity of the extended ADL scale (EADL) and to test its sensitivity to change. Three hundred and sixty-one consecutive acute stroke admissions were recruited and surveyed at one, six and 12 months after stroke, using the EADL. There were the expected correlations with the Barthel Index, Nottingham Health Profile, Geriatric Depression Score and the London Stroke Satisfaction Score. Logistic regression analysis showed that, although men were more mobile, they were less likely to carry out domestic and kitchen tasks. Also, nonwhites were more disabled, owner-occupiers had higher leisure scores and those living alone had higher kitchen scores. Analysis of effect sizes showed that the EADL is sensitive to the changes that occur after stroke and would be sensitive to the effect of an intervention that produced a change in independence of two or more ADLs. The EADL is a valid measure of the performance of instrumental ADLs and is sensitive to clinically important changes.