A Process Evaluation in a Randomized Controlled Trial among Adults with Acetabular Dysplasia

Abstract Introduction The 2021 framework from the UK’s Medical Research Council defines evaluation as a theory-driven approach to examine how well an intervention works. However, the application of these guidelines can be challenging. Therefore, using a process evaluation case study on an exercise and patient education intervention for adults with acetabular dysplasia, we reflect on which specific aspects were relevant for the evaluation of the intervention and why. We focus on detailing methods to assess implementation (process, dose, reach), acceptability, mechanisms of change, and the impact of contextual factors. Methods Two hundred trial participants aged 18-50 years will be recruited from a University Hospital in Denmark and randomised to intervention and control groups. The process evaluation adopts a concurrent mixed-methods design involving self-report questionnaires at baseline and 6-month follow-up, training records and semi-structured focus groups with intervention providers (n = 10) and healthcare managers (n = 4-6). The mechanisms of change will be explored through semi-structured one-to-one interviews (at baseline and 6-month follow-up) with 15-20 purposefully sampled trial participants, and additionally, through exploratory examinations of associations between dose and change in health outcomes at 6-month follow-up), via simple linear regression models. The acceptability and contextual factors will be explored through one-to-one participant interviews, plus focus groups with 4-6 healthcare managers. Thematic analyses of the interviews will focus on expectations, experiences, events, personal understandings and interpersonal and organisational interactions. Conclusions The presentation will explore how the operational aspects of the intervention can be assessed through a process evaluation and how these findings may improve and expand any future implementation efforts.