Development of a complex intervention to improve mobility and participation of older people with vertigo, dizziness and balance disorders in primary care: a mixed methods study.

BACKGROUND: Vertigo, dizziness and balance disorders (VDB) are common in older people and cause restrictions in mobility and social participation. Due to a multifactorial aetiology, health care is often overutilised, but many patients are also treated insufficiently in primary care. The purpose of this study was to develop a care pathway as a complex intervention to improve mobility and participation in older people with VDB in primary care. METHODS: The development process followed the UK Medical Research Council guidance using a mixed-methods design with individual and group interviews carried out with patients, physical therapists (PTs), general practitioners (GPs), nurses working in community care and a multi-professional expert panel to create a first draft of a care pathway (CPW) and implementation strategy using the Consolidated Framework of Implementation Research and the Expert recommendations for Implementing Change. Subsequently, small expert group modelling of specific components of the CPW was carried out, with GPs, medical specialists and PTs. The Behaviour Change Wheel was applied to design the intervention´s approach to behaviour change. To derive theoretical assumptions, we adopted Kellogg´s Logic Model to consolidate the hypothesized chain of causes leading to patient-relevant outcomes. RESULTS: Individual interviews with patients showed that VDB symptoms need to be taken more seriously by GPs. Patients demanded age-specific treatment offers, group sessions or a continuous mentoring by a PT. GPs required a specific guideline for diagnostics and treatment options including psychosocial interventions. Specific assignment to and a standardized approach during physical therapy were desired by PTs. Nurses favoured a multi-professional documentation system. The structured three-day expert workshop resulted in a first draft of CPW and potential implementation strategies. Subsequent modelling resulted in a CPW with components and appropriate training materials for involved health professionals. A specific implementation strategy is now available. CONCLUSION: A mixed-methods design was suggested to be a suitable approach to develop a complex intervention and its implementation strategy. We will subsequently test the intervention for its acceptability and feasibility in a feasibility study accompanied by a comprehensive process evaluation to inform a subsequent effectiveness trial. TRIAL REGISTRATION: The research project is registered in "Projektdatenbank Versorgungsforschung Deutschland" (Project-ID: VfD_MobilE-PHY_17_003910; date of registration: 30.11.2017).