Capturing process and outcome in complex rehabilitation interventions: A "Y-shaped" model.

A complex and dynamic set of biological, psychological and social factors interact to determine the consequences of acquired brain injury (ABI). This has led to recognition of the need for an integrated biopsychosocial approach to assessment, formulation and rehabilitation after ABI, drawing on multiple methods and models. This presents a significant challenge for the development and evaluation of complex rehabilitation programmes that may involve multiple interventions. In psychotherapy research, such problems are addressed through an approach which emphasises theoretical modelling of the disorder from which treatment programmes are developed and then evaluated. The resulting outcome studies, in which theoretically grounded change processes are measured, thus provide not only a test of the efficacy of the intervention but also an empirical evaluation of the underpinning model. In this paper we advocate such an approach to ABI rehabilitation, and to this end propose a model of the change process in rehabilitation called the "Y-shaped" model. This integrates findings from research into psychosocial adjustment, awareness and well-being following brain injury. The notion of discrepant or threatened identity is central to the model. Specific interventions are identified from the model, along with processes and interactions that may be central to change in rehabilitation. In conclusion, we propose that development of integrated models of change in rehabilitation is required. We also note that outcome should focus not only on level of activity or social participation, but also on the personal meaning of this to the person with brain injury.