Reinie has a track record of conceptualising and testing the efficacy of psychosocial interventions for children with behavioural and emotional disorders. Theoretically, his main research interests lie at the intersections between health and social care, and phenomena specific to different population groups. The overarching theme of his research is promoting the social inclusion of children with developmental disorders, developing evidenced-based psychosocial interventions and instrument development. A major focus for his research is on how to ensure that people from different populations and social strata experience participation, remain engaged, socially connected and live healthy lives. His work is applied and intended to influence practice, so he investigates service-delivery arrangements and intervention techniques in terms of how well they achieve such outcomes.