Creating system-wide change in medicine: The role of implementation science in achieving scale and adoption

Delivering meaningful change in healthcare is less about new discoveries and more about ensuring adoption at scale of what is already known to work. Implementation science (IS) studies the methods that support systematic uptake of evidence-based practices into routine care. Yet traditional strategies - like policy mandates, staff training alone, or the passive spread of information - often fail to deliver sustained change. This paper introduces the foundational principles of IS, critiques conventional approaches, and shares lessons learned from national-scale digital implementation efforts in Wales. Key IS enablers, including leadership, stakeholder alignment, readiness and feedback systems, are described in practical terms. We aim to make IS accessible for healthcare leaders and clinicians seeking to reduce variation and embed innovation at scale.