Americans spend nearly $2 trillion on health care each year. U.S. hospitals, physicians, nurses, and other health care providers offer some of the best care in the world, but far too many people still do not receive the quality of care that they expect, deserve, and purchase. The health care system in the United States is working to improve the quality of care. These changes require that health care providers, policymakers, and consumers get accurate, unbiased information in order to make the best decisions along with tools and practices they can use to improve the Nation's health care system. The Agency for Healthcare Research and Quality (AHRQ), 1 of 12 agencies within the Department of Health and Human Services (HHS), is committed to helping the nation improve our health care system. AHRQ's mission is to improve the quality, safety, efficiency, and effectiveness of health care for all Americans. To fulfill this mission, AHRQ conducts and supports health services research that: Reduces the risk of harm from health care services by using evidence-based research and technology to promote the delivery of the best possible care; Transforms research into practice to achieve wider access to effective health care services and reduce unnecessary health care costs; Improves health care outcomes by encouraging providers, consumers, and patients to use evidence-based information to make informed treatment choices/decisions. The Agency's mission and goals help HHS achieve the objectives set forth in the Secretary's 2006 priority initiatives, especially those of health care transparency, health care technology, value-based health care, Medicaid modernization, personalized health care, prevention, and public health preparedness. This report presents key findings from AHRQ's research portfolio during 2006.