A Rasch-based validation of a short version of ABILHAND as a measure of manual ability in adults with unilateral upper limb amputation.

Abstract

To evaluate the measurement properties of ABILHAND (a generic measure developed to assess functioning in people with upper limb impairments) when used in adults with unilateral upper limb amputation (ULA). A convenience sample of 72 adults who had unilateral ULA and completed rehabilitation at the Institute for Rehabilitation in Ljubljana at least 1 year prior to the study. They filled in the ABILHAND questionnaire. Rating scale analysis (Rasch model) was used to evaluate functioning of the rating scale categories, the validity of the measure by examining fit of the items to the latent trait and the hierarchy of item difficulties compared with expectations of the construct. Rasch analysis allowed us to improve ABILHAND by rescoring to reduce the response categories from 5 to 4, and identifying 22 of 46 items that are useful to measure upper limb function in people with ULA. The results indicate that high confidence can be placed in the consistency of both person-ability and item-difficulty estimates. This revised ABILHAND for people with unilateral ULA (ABILHAND-ULA 1.0) is a promising instrument for measuring their degree of manual functioning.