Abstract
<title>Abstract</title> <p> <bold>Introduction</bold> Competency-based medical education (CBME) requires effective implementation at the meso-level of clinical training units, where educational supervisors translate policy into practice. Yet supervisors are often appointed for clinical expertise rather than educational preparation, creating a capability gap that undermines CBME implementation. This study evaluated a structured faculty development programme designed to build supervisory capability across four key domains. <bold>Methods</bold> A mixed-methods study evaluated a 12-week blended learning programme for Supervisors of Training (SOTs) across three postgraduate training pathways in Hong Kong. The programme addressed four competency domains: facilitating competency-based learning, fostering supportive clinical environments, conducting in-training assessment, and supporting trainees in difficulty. Quantitative data were collected using adapted CPD-Reaction Questionnaires, grounded in the Theory of Planned Behaviour, from 15 participants with matched pre- and post-course surveys. Two post-programme focus groups with 17 participants total provided qualitative data analysed using thematic analysis, with findings integrated via a joint display. <bold>Results</bold> Quantitative findings showed large self-reported effect size estimates for self-efficacy across three competency domains (Cohen's d = 0.83–0.96) and for social influence across two domains (d = 0.84–1.04); scores for moral norm and beliefs about consequences showed more modest increases, consistent with high pre-course baseline scores. Seven qualitative themes described acquisition of structured supervisory frameworks, reconceptualisation of assessment as formative, heightened awareness of the clinical learning environment, broadened perspectives on trainee difficulty, and calls to extend training beyond designated supervisors to build capability for cultural change. <bold>Discussion</bold> The preparation gap appeared to reflect limited capability rather than limited motivation — a distinction favouring structured frameworks and experiential learning in programme design. The cohort-based design appeared to shift perceived collegial norms, suggesting faculty development may strengthen shared professional expectations alongside individual capability. Sustainable CBME implementation nonetheless requires coordinated strategies aligned across institutional, supervisory, and frontline levels of the training system. </p>