Group intervention studies in the cognitive rehabilitation of individuals with traumatic brain injury: challenges faced by researchers.

There are many factors to consider in designing and interpreting group studies. These include both analytic considerations, such as the selection of valid and reliable outcome measures, and subjective considerations, such as the selection of outcomes that are perceived to be important to participants and researchers. In this paper, we review key issues to consider in the design of group studies in neurorehabilitation, using problem-solving studies in traumatic brain injury as an example.