Improving Lynch syndrome detection: a mixed-methods process evaluation of a hybrid type III effectiveness-implementation trial

Introduction: Translating evidence-based practices into real-world healthcare settings is challenging, particularly in the rapidly evolving field of genomics. A pragmatic two-arm cluster-randomized clinical trial (Hide and Seek Project - HaSP) tested two implementation approaches for improving hereditary cancer referral practices with one key distinction: implementation strategies that were designed 1) explicitly using psychological theory, or 2) using healthcare professional intuition. This mixed-methods process evaluation aimed to provide insights into how and why change occurred by examining contextual determinants, identifying mechanisms of action, and exploring the role of theory.

Methods: Post-implementation interviews were conducted with Implementation Leads and clinicians from participating HaSP sites. Transcripts were analysed using a mixed inductive and deductive approach, guided by the updated Consolidated Framework for Implementation Research (2.0). Findings were triangulated with other HaSP process evaluation data sources, including HaSP focus group observations, HaSP research team focus groups, MDT observations, and Implementation Lead project logs. Logic models and case studies were developed to articulate causal processes underlying strategy effectiveness and conditions necessary for implementation success.

Results: Eighteen participants from seven HaSP sites were interviewed. Qualitative analysis identified themes related to Lynch syndrome complexity, pandemic disruptions, operational challenges, information technology constraints, multidisciplinary collaboration, cultural determinants, attitudes towards change, the value of theory, adaptations, and implementation support. Within these themes, a total of 39 contextual determinants were identified, with barriers and facilitators spanning 18 CFIR constructs across five domains. Logic models and case studies highlighted a number of mechanisms of action, producing variable clinical outcomes. Process evaluation findings, interpreted together with HaSP trial outcomes, indicate that theory-based implementation strategies may better support Lynch syndrome detection practices compared to intuition-based strategies.

Conclusions: The information gained from this process evaluation deepens understanding of the factors influencing the success of hospital-specific implementation strategies within the HaSP framework. Potential pathways for optimising the effectiveness of the overall HaSP implementation approach have been identified.

Trial registration: Australian New Zealand Clinical Trials Registry, ACTRN12618001072202. Registered 27 June 2018, https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=375348&isReview=true .