Patient adherence to medical advice is essential for improving clinical outcomes, reducing healthcare costs, and enhancing patient quality of life. However, existing research often fails to systematically examine how specific forms of patient involvement and provider engagement jointly influence adherence, leading to fragmented findings. Grounded in the value co-creation (VCC) framework, this study integrates patient involvement (self-directed vs. collaborative) with provider engagement (facilitator vs. orchestrator) to examine their combined effects on adherence. Using a meta-analysis of 371 effect sizes from 120 studies, we quantify the impacts of different VCC manifestations and explore how contextual factors—such as patient demographics, industry type, and country characteristics—moderate these relationships. For instance, our findings reveal that orchestrator is more effective for self-directed patients, while facilitator shows consistently lower impact across involvement types. By synthesizing existing evidence, this study provides actionable insights for healthcare providers and policymakers to improve patient adherence across diverse contexts.
