Collaborative model of care between orthopaedics and allied health professionals in knee osteoarthritis (CONNACT): process evaluation of an effectiveness-implementation hybrid randomized control trial.

Objective: To evaluate the implementation process of a community-based, multidisciplinary intervention (CONNACT) through a randomized controlled trial (RCT) in order to contextualize the RCT outcomes and inform implementation opportunities.

Methods: This study is an embedded qualitative process evaluation of the CONNACT effective-implementation hybrid RCT. Semi-structured interviews with 22 intervention patients and 14 healthcare professionals were conducted. Interviews were audio-recorded, transcribed and translated using framework analysis. Data was analysed thematically and the emergent themes were organised into the conceptual domains of RE-AIM. An explanatory sequential methods approach was used to discuss the Reach and Effectiveness domains of RE-AIM, whereby quantitative data (i.e. recruitment logs and published quantitative results) was discussed in relation to this study's qualitative data.

Results: Reach: 55.4% of the patients who met the inclusion criteria participated, while work or family commitments and disinterest in physiotherapy are the primary reasons for declining participation.

Effectiveness: CONNACT intervention is not superior to control hospital-based usual care in terms of pain, function, and quality of life, but superior in physical performance, knee satisfaction, global perceived effect and positive dietary change. The results and effectiveness of CONNACT are presented and discussed in a related publication. Adoption: Healthcare professionals proposed changes for long-term sustainability (transdisciplinary approach, expert patients) despite their strong support for CONNACT. Implementation (context): A spectrum of passive-resigned and impatient-unrealistic mindsets, pain beliefs, and expectations was elucidated. Implementation (mechanism of impact): Focus on patient education and empowerment encouraged patients to actively accept their condition and practice self-efficacy. Although group classes are a source of support, motivation, and positive peer pressure, several patients preferred personalized treatments. CONNACT's synergistic nature benefitted patients who are more complex. Maintenance (patient-level): Patients highlighted the importance of incorporating exercise into their regular routines, but lack of time and inertia remain as significant barriers.

Conclusion: The themes have allowed a better understanding of the RCT primary and secondary outcomes and informed the next phase of implementation. CONNACT and similar interventions should identify and address reasons for refusing participation [Reach]; improve group classes with initial evaluations, equal attention paid to patients, tailored exercises, and acknowledge progress [Effectiveness, Implementation]; and adopt a streamlined resource-efficient transdisciplinary design [Maintenance].

Trial registration: This study, which primarily employs qualitative methods for data collection, is not a clinical trial (clinical trial number: not applicable). Ethics approval (NHG DSRB ref no: 2020/00067;) was obtained before commencement of this study.