Background: Reduced social competence and social integration following acquired brain injury (ABI) is well-documented. There is evidence that group social communication interventions for people with ABI and training for neuro-typical communication partners can be more effective than training the person with ABI alone. This study explores the effectiveness of a peer-led group intervention based on claims that peer models are a more powerful mechanism for learning and behaviour change than interventions led by a clinician. A peer-led training model for social communication has not previously been tested in ABI. Method: Twenty-four participants with severe ABI were recruited from a residential post-acute neurorehabilitation centre. An experimental parallel group design was used to compare a peer-led group intervention to a social activity group (usual care). A pilot study tested the feasibility of the approach followed by a main study. The groups ran for 8 weeks. A peer facilitator was trained in sixteen individual sessions over 4 weeks with a clinician. Behaviour was measured twice at baseline, after intervention and at maintenance. Four primary outcome measures, including the Adapted Measure of Participation in Conversation (MPC), and a newly devised measure of conversational interaction evaluated change in group communication behaviours. Results: Groups did not differ in baseline behaviour. There were significant differences in the treated group on the MPC and the measure of conversational interaction post-intervention. The treated group showed a more balanced interaction post-intervention and at follow-up. However, outcome measures showed differential sensitivity. Conclusion: There is preliminary evidence of advantage for peer-led groups in ABI intervention. The new conversational measure shows promise as a method to detect change in group communication behaviour
