Evaluating an intervention to increase meaningful activity after severe traumatic brain injury: A single-case experimental design with direct inter-subject and systematic replications.

Severe traumatic brain injury (sTBI) often results in significant morbidity, with fewer than 50% returning to work and only a minority resuming leisure and social activity. Yet few effective interventions are available for non-vocational activity. The aim of the study was to develop a new goal-directed intervention, the Programme for Engagement, Participation and Activities (PEPA), and evaluate its effect. The research design was a multiple-baseline design across behaviours, with direct inter-subject and systematic replications. Seven participants with sTBI, neurobehavioural impairment including apathy, inability to work, and limited leisure/social activities were categorised into two groups. Group 1 (n = 4) had cognitive impairments but were functionally independent. Systematic replication was conducted in a further three participants (group 2) with major neurobehavioural impairments and functional disability. Generalisation measures evaluated other life domains in group 1 participants (e.g., mood, community participation). Results of the weighted average Tau-U across the tiers was significant for six out of seven participants, with large effect sizes (>=.64) for five participants. Generalisation effects extended to other domains of life. The PEPA thus shows promise as an effective intervention to increase non-vocational activity and improve mental health outcomes in people with neurobehavioural disability after sTBI. These results add to the evidence for the effectiveness of goal-directed interventions.