Statistical analysis plan for the stepped wedge clinical trial Healing Right Way—enhancing rehabilitation services for Aboriginal Australians after brain injury

Background Aboriginal Australians are known to suffer high levels of acquired brain injury (stroke and traumatic brain injury) yet experience significant barriers in accessing rehabilitation services. The aim of the Healing Right Way trial is to evaluate a culturally secure intervention for Aboriginal people with newly acquired brain injury to improve their rehabilitation experience and quality of life. Following publication of the trial protocol, this paper outlines the statistical analysis plan prior to locking the database. Methods The trial involves a stepped wedge design with four steps over 3 years. Participants were 108 adult Aboriginal Australians admitted to one of eight hospitals (four rural, four urban) in Western Australia within 6 weeks of onset of a new stroke or traumatic brain injury who consented to follow-up for 26 weeks. All hospital sites started in a control phase, with the intervention assigned to pairs of sites (one metropolitan, one rural) every 26 weeks until all sites received the intervention. The two-component intervention involves training in culturally safe care for hospital sites and enhanced support provided to participants by Aboriginal Brain Injury Coordinators during their hospital stay and after discharge. The primary outcome is quality of life as measured by the Euro QOL–5D-3L VAS. A mixed effects linear regression model will be used to assess the between-group difference at 26 weeks post-injury. The model will control for injury type and severity, age at recruitment and time since commencement of the trial, as fixed effects. Recruitment site and participant will be included as random effects. Secondary outcomes include measurements of function, independence, anxiety and depression, carer strain, allied health occasions of service received and hospital compliance with minimum processes of care based on clinical guidelines and best practice models of care. Discussion The trial will provide the first data surrounding the effectiven