Inter- and intra-rater reliability and clinical utility of the Brachial Plexus Outcome Measure: A pilot study

Introduction Birth-related plexus injuries cause paralysis of the upper limb. The majority of patients spontaneously recover, but many suffer with long-term limitations in function. The Brachial Plexus Outcome Measure was developed to assess upper limb function in children with birth-related plexus injuries. This pilot study assessed the inter- and intrarater reliability in novice users. Information was also gained with regards to the perceived clinical utility of the tool. Methods Eleven therapists, experienced in the treatment of birth-related plexus injuries but naïve in the use of the Brachial Plexus Outcome Measure, were recruited as raters. Eight video-recorded assessments were independently scored. Four raters were randomly selected to repeat two of the analyses. The perceived clinical utility of the Brachial Plexus Outcome Measure was investigated via a questionnaire. Results Across the domains of the Brachial Plexus Outcome Measure, the majority of items scored ‘Fair’ for inter-rater reliability with kappa scores ranging from 0.13–0.46. Intra-rater agreement was better with the majority of items scoring 0.44–0.86 upon weighted kappa analysis. Participant scores for clinical utility were mixed. However, 7 of the 11 raters agreed that the Brachial Plexus Outcome Measure is useful as a pre- and post-intervention tool. Conclusions When compared to the inter-rater reliability of similar functional outcome measures, these results are less favourable. Future research and suggestions to improve the implementation, reliability and clinical utility of the Brachial Plexus Outcome Measure have been identified. These include better standardisation of equipment and improved instructional guidance. In addition, within the clinical setting, it is recommended that the same clinician assesses the same child over the course of their treatment.