Variability in measuring (instrumental) activities of daily living functioning and functional decline in hospitalized older medical patients: a systematic review

Objective: To study instruments used and definitions applied in order to measure (instrumental) activities of daily living (I [ADL]) functioning and functional decline in hospitalized older medical patients. Study Design: We systematically searched Medline, Embase, and the Cochrane Database of Systematic Reviews from 1990 to January 2010. Articles were included if they (1) focused on acute hospitalization for medical illness in older patients; (2) described the instrument used to measure functioning; and (3) outlined the clinical definition of functional decline. Two reviewers independently extracted data. Results: In total, 28 studies were included in this review. Five different instruments were used to measure functioning: the Katz ADL index, the IADL scale of Lawton and Brody, the Barthel index, Functional Independence Measure, and Care Needs Assessment. Item content and scoring between and within the instruments varied widely. The minimal amount for decline, as defined by the authors, referred to a decrease in functioning between 2.4% and 20.0%. Conclusion: This review shows there is a large variability in measuring (I)ADL functioning of older hospitalized patients and a large range of clinical definitions of functional decline. These conceptual and clinimetric barriers hamper the interpretation and comparison of functional outcome data of epidemiological and clinical studies. (C) 2011 Elsevier Inc. All rights reserved.