Concurrent and construct validity of scores on the timed movement battery

Background and Purpose. The Timed Movement Battery (TMB) is a new assessment tool designed to measure mobility in elderly individuals. "Mobility" was defined as a person's ability to maneuver his or her body independently in order to accomplish everyday tasks. The purpose of this study was to assess the concurrent and construct validity of scores obtained with the TMB as a measure of mobility in a group of elderly individuals who reported moderate or no difficulty in performing either basic or instrumental activities of daily living (BADL or IADL). Subjects. Thirty community-dwelling elderly people, with a mean age of 77.5 years (SD=7.0, range=65-92), participated in this study. Methods. Subjects responded to 2 questionnaires regarding their activities of daily living (ADL) (ie, Barthel Index and an 18-item ADL/IADL scale) and completed 3 assessments of mobility (ie, Berg Balance Scale, Timed "Up sc Go" Test, and the TMB). Subjects were asked to perform the items on the TMB at a "self-selected" speed (their normal speed) and at a "maximum-movement" speed (as quickly as they could safely perform the items). Subjects' scores on the TMB were cross-correlated with data for 3 criterion tests (ie, Berg Balance Scale, Timed " Up & Go" Test, Barthel Index, and the 18-item ADL/IADL scale) using Spearman rank correlations and Pearson product moment correlations. Results. Composite scores of the TMB performed at self-selected speeds correlated highly with data for the criterion tests and differentiated between those subjects reporting difficulty with ADL and those reporting no difficulty. Conclusion and Discussion. These results support the validity of scores obtained with the TMB as a measure of mobility in this sample of elderly individuals with moderate or no reported difficulty with ADL.