Development and validation of a performance-based measure of upper extremity functional limitation

Abstract

While the standardized lower extremity physical performance battery (LEPPB) is widely used to measure lower body functional limitation, no corresponding measure has been developed for upper body functional limitation. We combined three standard measures (William's Hand Test, Hand Signature, Functional Reach) to develop an upper extremity physical performance battery (UEPPB) analogous to the LEPPB, and examined its validity. We used baseline data from a community-dwelling cohort of 749 Mexican American and European American elders and combined times to complete the William's Hand Board, Hand Signature, and distance on Functional Reach into a single composite measure, using scoring methods analogous to those for the LEPPB. We summarize concurrent, discriminant, and construct validity evidence for the UEPPB, based on observed associations with established measures of physical functional limitation, disability, and dependence. All correlations were in the expected direction. Shared variance with self-reported upper and lower extremity functional limitation was 10 and 5%, respectively, and with self-reported ADL disability, ADL dependency, and IADL dependency it was 32, 26, and 31%, respectively. In multivariate models of self-reported and performance-based disability and dependency, the UEPPB and LEPPB made significant, independent contributions and, net of contextual variables (age, sex, ethnic group, education, income) explained 4 to 10% of the variance in disability and dependency. The UEPPB is a valid performance-based measure of upper extremity functional limitation and makes an independent contribution beyond LEPPB in explaining disability and dependence.