Health care helps people stay healthy, recover from illness, live with chronic disease or disability, and cope with dying. Quality health care delivers these services in a way that is safe, timely, patient centered, efficient, and equitable. Unfortunately, Americans too often do not receive care that they need or they receive care that causes harm. Care can be delivered too late or without full consideration of a patient's preferences and values. Many times, our system of health care distributes services inefficiently and unevenly across populations. Each year since 2003, the Agency for Healthcare Research and Quality (AHRQ), together with its partners in the Department of Health and Human Services (HHS), has reported on progress and opportunities for improving health care quality, as mandated by the U.S. Congress. The information amassed for the National Healthcare Quality Report (NHQR) since its inception is a growing knowledge base that addresses two critically important questions: What is the status of health care quality in the United States? How is the quality of the health care delivered to Americans changing over time? The significance of tracking this sector's performance is evident from many vantage points. More than $2 trillion is spent each year on health care in the United States, and costs are escalating relentlessly, threatening the financial security of families and businesses. Quality and value are increasingly considered in decisions made by patients and payers. To help patients choose doctors and hospitals prudently, tools have been produced that gather information about and rate providers. To motivate providers to deliver high-quality care, purchasers are starting to reward superior performance and refusing to pay for additional care needed to correct medical errors. This is a dynamic area that will likely continue to develop and affect ways in which care is selected, delivered, and paid for. Monitoring the success of these efforts is crucial as stakeholders refine their quality improvement activities and reassure Americans that they are receiving the optimal health care they deserve. The NHQR is built on 220 measures categorized across four dimensions of quality: effectiveness, patient safety, timeliness, and patient centeredness. Guided by a subcommittee of AHRQ's National Advisory Council and an HHS Interagency Work Group, i this year's report focuses on the state of health care quality for a group of 45 core report measures that represent the most important and scientifically credible measures of quality for the Nation. By focusing on 45 core measures, the 2008 report provides a more readily understandable summary and explanation of the key results derived from the data.ii While the measures selected for inclusion in the NHQR are derived from the most current scientific knowledge, this knowledge base is not evenly distributed across the dimensions of health care quality. For example, there are many measures on the effectiveness of care for heart attacks, but few measures of medication safety or end-of-life care. The analysis in the following pages centers on measures for which data are available and fit within a framework provided by the Institute of Medicine. Three themes from the 2008 NHQR emphasize the need to accelerate progress if the Nation is to achieve high-quality health care. These themes also reflect the challenges that still remain: Health care quality is suboptimal and continues to improve at a slow pace; Reporting of hospital quality is leading improvement, but patient safety is lagging; Health care quality measurement is evolving, but much work remains