Translation and internal content validation of the Swedish version of the Brachial Assessment Tool (BrAT)

To translate and culturally adapt the Brachial Assessment Tool (BrAT) into Swedish and evaluate the internal consistency, and internal content validity using Rasch analysis in patients with traumatic brachial plexus injuries (TBPI).

The translation was made in accordance with international guidelines. TBPI patients were identified in clinical records. The BrAT-Swe was sent out to patients by post. Internal consistency was assessed using Cronbach alpha and content validity using Rasch analysis evaluating fit to the Rasch model, threshold response, local dependency, dimensionality, differential item functioning (DIF), and targeting.

The translation of the BrAT was completed without major discrepancies. A total of 164 patients completed the BrAT-Swe. Internal consistency ranged from 0.90 to 0.98. Rasch analysis supported the content validity. All subscales demonstrated fit to the model with no local dependency, minimal disordered thresholds and no unidimensionality. Uniform DIF for item 6 by age, was identified. Minimal differences in hierarchical ordering were identified.

This study presents a Swedish translation of the BrAT (BrAT-Swe) and has demonstrated that the translated BrAT-Swe is well adapted for Swedish circumstances. Analysis supports the internal content validity of the BrAT-Swe as a unidimensional targeted PROM designed to assess activity limitation after TBPI.