Background: The risk for obesity is twice as high in people with serious mental illness (SMI) compared to the general population. Racial and ethnic minority status contribute additional health risks. The aim of this study is to describe the protocol of a Hybrid Trial Type 1 design that will test the effectiveness and examine the implementation of a peer-led healthy lifestyle intervention in supportive housing agencies serving diverse clients with serious mental illness who are overweight or obese.
Methods: The Hybrid Trial Type 1 design will combine a randomized effectiveness trial with a mixed-methods implementation study. The effectiveness trial will test the health impacts of a peer-led healthy lifestyle intervention versus usual care in supportive housing agencies. The healthy lifestyle intervention is derived from the Group Lifestyle Balanced Program, lasts 12 months, and will be delivered by trained peer specialists. Repeated assessments will be conducted at baseline and at 6, 12, and 18 months post randomization. A mixed-methods (e.g., structured interviews, focus groups, surveys) implementation study will be conducted to examine multi-level implementation factors and processes that can inform the use of the healthy lifestyle intervention in routine practice, using data from agency directors, program managers, staff, and peer specialists before, during, and after the implementation of the effectiveness trial.
Discussion: This paper describes the use of a hybrid research design that blends effectiveness trial methodologies and implementation science rarely used when studying the physical health of people with SMI and can serve as a model for integrating implementation science and health disparities research. Rigorously testing effectiveness and exploring the implementation process are both necessary steps to establish the evidence for large-scale delivery of peer-led healthy lifestyle intervention to improve the physical health of racial/ethnic minorities with SMI.
Trial registration: www.clinicaltrials.gov; NCT02175641, registered 24 June 2014.