Methods: Mechanisms identified in a prior realist synthesis of opioid agonist therapy continuing professional development programs were iteratively tested and refined using purposive and opportunistic sampling and realist approaches against two systematic reviews of programs in analgesic prescribing and palliative care. Further testing involved practical application within programs in sustainable health care and pain management.

Results: Ninety reports on 75 programs and practical application to multiple additional programs informed the final model consisting of five distinct mechanisms: motivation transformation, expert influence, confidence development, self-efficacy facilitation, and community of practice expansion. The mechanisms and related analysis emphasize that continuing professional development is heterogeneous, complex, and context dependent.

Discussion: Shifting toward outcome-based and theory-based approaches facilitates further conceptual shifts at intraprogram and interprogram and interintervention levels toward more deliberate program development and evaluation, increased program complementarity and subsequent collaboration. It clarifies opportunities for intercalation of continuing professional development with other intervention sciences. The model presents a resource for practitioners, researchers, and policymakers to advance continuing professional development planning, coordination, and evaluation.