Is Coronary Intensive Care Unit Volume a Quality Metric?

F aced with a serious medical condition, care at a highvolume center would be generally supported by research. Across the medical, surgical, and critical care literature, annual institutional and individual physician volumes have been associated with improved patient outcomes in observational studies. For surgical or invasive procedures where an operator’s skills and judgment are related clinical outcomes, the evaluation and establishment of minimum annual volumes to maintain procedural competency are more straightforward. The task of benchmarking minimum annual institutional or care-unit volumes for the care of common medical conditions, however, is confounded by the interplay of regional, institutional, and individual care-provider differences layered over the patient population characteristics and the environment in which the medical services are located (Figure). Consequently, the evaluation and establishment of institutional or care-unit volume as a quality metric that is clearly evidence-based, reproducible, and defensible is a far more problematic endeavor.