Age-Friendly Health Care Systems: State of the Science, Past and Future Directions.

Global population aging presents an urgent challenge and significant opportunity to transform how health systems deliver care to older adults. The Age-Friendly Health Systems (AFHS) initiative, grounded in the 4Ms framework-What Matters, Medication, Mobility, and Mentation-was developed to improve outcomes for older adults by promoting optimal function, supporting autonomy in care decisions, and preventing iatrogenic complications. AFHS offers a comprehensive, integrated approach that can be implemented across diverse care settings. However, much of the existing evidence on AFHS effectiveness focuses on implementation processes rather than outcomes that reflect older adults' lived experiences and overall well-being. Moreover, current research highlights fragmentation in model evaluation, with considerable variability in how the 4Ms are implemented and measured. The current Annual State of the Science Review synthesizes existing studies on 4Ms implementation, examines the measures used, identifies barriers and facilitators to implementation, and outlines future directions for advancing AFHS research and practice.