The overall impact of managed care remains widely debated. Proponents argue that it has increased efficiency, improved overall standards, and led to a better understanding of the relationship and quality. They argue that there is no consistent, direct correlation between the cost of care and its quality, pointing to a 2002 Juran Institute study which estimated that the "cost of poor quality" caused by overuse, misuse, and waste amounts to 30 percent of all direct healthcare spending. The emerging practice of evidence-based medicine is being used to determine when lower-cost medicine may in fact be more effective.