Assessing Bilateral Upper Extremity Integration Using the Bilateral Task Assessment: Reliability and Validity Testing

The Bilateral Task Assessment (BTA) was developed to address the need for a clinically relevant and feasible measure of bilateral upper extremity function. The assessment was administered by occupational therapists as part of standard care to 4,362 individuals receiving inpatient rehabilitation. Retrospective data were analyzed using multiple psychometric methods to evaluate internal consistency, concurrent validity, to determine dimensionality, and item response theory (IRT) to calculate scores and assess task difficulty. Both individual task scores and completion times were analyzed. Results demonstrated good internal consistency for both task scores (0.92) and time scores (0.85). Factor analysis revealed a large effect size for task scores and a moderate effect size for completion times. Rating scale analyses further supported high internal consistency (0.92) and strong item-to-total correlations (0.86-0.90). Concurrent validity analyses identified significant correlations between the BTA and seven established measures of upper extremity function. Overall, findings indicate that the BTA is a valid, reliable, and feasible assessment that effectively evaluates bilateral upper extremity integration within a functional rehabilitation context.