Integrating theory and practice: the core components guide for rigorous quality improvement design.

Quality improvement (QI) methods have been used extensively to support the delivery of safe, timely, effective, equitable, and cost-effective health care. While QI initiatives have demonstrated benefits, critical gaps in design and implementation undermine their impact. Systemic reviews and expert commentaries point to recurring challenges, including limited understanding and appreciation of the system in which the work takes place; poorly articulated aims; absence of guiding content theories for scalable implementation; weak implementation strategies; inadequate mechanisms for measurement, evaluation, and learning; and insufficiently structured approaches to communication and dissemination. These gaps limit learning, impact, replication, sustainability and scalability. To address these gaps, the Institute for Healthcare Improvement (IHI) developed the Core Components Guide, a practical framework for designing, implementing, and evaluating QI initiatives. Grounded in Deming's System of Profound Knowledge and the Model for Improvement, the guide includes six interrelated components: System Understanding, Improvement Aim, Measurement, Evaluation and Learning, Content Theory, Execution Theory, and Dissemination and Communication. Together, these components provide a structured approach to align interventions with context, clarify program theory, and embed iterative learning cycles. This manuscript introduces the Core Components, illustrates their application through a case study, and shares lessons learned from operationalizing the guide across diverse settings. By integrating improvement and implementation science principles, the Core Components Guide strengthens design, promotes fidelity, and increases the potential for impact, replication, scale, and sustainability of QI initiatives. This Guide offers actionable strategies for QI leaders and policymakers to build stronger foundations for improvement, evaluation, and dissemination.