Outcome measurement instruments for adult brachial plexus injury: A systematic review of development and measurement properties

Purpose: To review candidate outcome measurement instruments (OMIs) for the core outcome set (COS) for brachial plexus injury (BPI) and identify those with the strongest measurement properties. Methods: We conducted a PRISMA-compliant systematic review to identify studies on the measurement properties of domain-specific OMIs for adult BPI. OMIs with adequate content validity were further evaluated. Two independent reviewers assessed the methodological quality of each study using the COSMIN Risk of Bias checklist and assessed overall quality using a modified GRADE approach. Results: Nineteen development/validation studies concerning nine OMIs were identified. The Brachial Assessment Tool (BrAT) and the Impact of Brachial Plexus Injury Questionnaire (IMBPIQ) (both measuring carrying out daily routine) had sufficient content validity to proceed to full evaluation. The BrAT had moderate quality evidence to support its psychometric properties. The IMBPIQ needs further research to evidence structural validity and internal consistency. The Brief Pain Inventory has strong psychometric properties in other populations and is recommended for the core measurement set (CMS) for chronic pain. Conclusions: The BrAT and the Brief Pain Inventory are recommended for inclusion in the BPI CMS. Further consensus work is needed to identify the most appropriate OMI for voluntary movement. Systematic Review Registration: PROSPERO (CRD42022307564).