In 1999, the Institute of Medicine (IOM) published To Err is Human, estimating that preventable medical errors caused 44,000 to 98,000 deaths each year in U.S. hospitals — more than motor vehicle accidents, breast cancer, or AIDS.¹ A year later, Crossing the Quality Chasm called for a 21st-century health system built on six aims: safe, effective, patient-centered, timely, efficient, and equitable care.²

Together, these reports reframed quality as a systems problem, not a matter of individual vigilance. Before 1999, healthcare largely operated under a “blame and train” mindset: when something went wrong, leaders focused on retraining and/or discipline. The IOM’s 1999 report shattered that narrative, showing that errors were rarely the result of mere negligence, instead arising from fragmented processes, poor communication, and hidden design flaws in systems. The report urged safeguards such as standardization, redundancy and feedback loops, laying the groundwork for a shift toward safety as a design principle.

High-risk industries such as aviation had already embraced this idea: safety comes from systems that anticipate human fallibility and prevent small errors from cascading, not from telling people to “try harder.” Just as aviation relies on checklists, incident reporting, and organizational learning, healthcare began to adopt similar principles and tools, recognizing them as essential for resilience. The 2000 report went further, declaring the U.S. health system “not designed for the 21st century” and calling for fundamental redesign around the six aims. The two reports shifted the conversation from episodic fixes to whole-system transformation.

Yet, a quarter-century later, many healthcare organizations still struggle to translate these principles into daily operations.

Persistent gaps in quality implementation

Despite measurable gains, implementation of the six IOM aims remains uneven. A 2020 scoping review of U.S. hospital performance found safety and effectiveness are commonly measured, while timeliness, patient-centeredness, and equity appear far less often in performance frameworks. Measures for timeliness (e.g., appointment wait times), patient-centeredness (e.g., shared decision-making), and equity (e.g., stratified outcomes by race or language) appear far less often in organizational dashboards and improvement plans. The scoping review’s point was that they were disproportionately underrepresented relative to their importance for holistic quality. Equity metrics, when present, were typically limited to risk adjustment rather than for identifying and closing disparities.³