An exercise and patient education intervention to reduce pain and physical limitations in individuals with developmental dysplasia of the hip: study protocol for a process evaluation integrated within a randomised controlled trial (the MovetheHip trial)

Abstract

Background The Movethehip trial investigates the effectiveness of an exercise and patient education intervention for adults with developmental dysplasia of the hip. The intervention involves eight tailored one-to-one sessions with trained providers who employ supportive feedback tools. This protocol reports a planned process evaluation, which aims to determine how the intervention functions by examining mechanisms of change, implementation of the intervention (process, dose and reach), its acceptability and the influence of contextual factors. Methods Two hundred trial participants aged 18–50 years will be recruited from a University Hospital in Denmark and randomised to the intervention or control group. Approximately ten providers will deliver the intervention. The process evaluation adopts a concurrent mixed-methods design. The mechanisms of change will be explored through semi-structured one-to-one interviews (at baseline and six-month follow-up) with 15–20 purposefully sampled participants and by measuring changes in health outcomes (self-reported pain, physical functioning and quality of life completed at baseline and at three- and six-month follow-up). The implementation will be assessed using self-report questionnaires (at baseline and six-month follow-up), training records and semi-structured focus group interviews with intervention providers (n = 10) and healthcare managers (n = 4–6). Additionally, change will be measured through an explorative examination of associations between dose and change in health outcomes, applying simple linear regression models. The acceptability of the intervention and the influence of contextual factors will be explored through one-to-one participant interviews and focus group interviews with 4–6 healthcare managers. The interviews will focus on expectations, experiences, events, personal understandings and interaction with interpersonal and organisational aspects. Interview data will be analysed using theoretical thematic analyses, and findings will be merged with quantitative data and reported jointly on a theme-by-theme basis. Discussion The process evaluation conducted as part of the MovetheHip trial will illuminate how the intervention works, and if the intervention is proven effective, the findings of the evaluation will contribute to pinpoint how the intervention may be optimised to facilitate future up-scaling and implementation. Trial registration The MovetheHip protocol was approved by the Committee on Health Research Ethics in the Central Denmark Region. ClinicalTrials, NCT04795843, 20 March 2021, https://classic.clinicaltrials.gov/ct2/show/NCT04795843.