Problems with quality of health care in the United States earned the attention of the public with, and have steadily gained in importance since, the release of the first in a series of Institute of Medicine (IOM) reports on this topic, "To Err is Human: Building A Safer Health System," in 1999. The release of the IOM report represented a changing approach to addressing suboptimal health care quality, from one focused primarily on quality assurance to one focused on quality improvement broadly through the realignment of systems of delivering and financing care to incentivize quality of care. This issue now occupies a prominent position on the national agenda for health care reform and is the subject of considerable congressional interest. Policy makers and others have offered a wide range of policy options to improve health care quality. This report provides information on the issue of quality measurement, which serves as the basis of several of the options policy makers are offering for addressing this problem. Specifically, recently introduced health reform bills have included a strong focus on supporting and expanding a coordinated national quality measurement infrastructure. These include efforts that would broadly support the development of national priorities in the area of performance measurement; the development of new quality measures and identification of gaps in existing measures; the expansion of the endorsement process for quality measures; and the delineation of a process, in rulemaking, for selecting and implementing new quality measures for use in public health care programs. This report begins with a brief description of health care quality activity conceptually, the types of quality information that support these activities, and how quality measurement can be placed within these frameworks. It provides a discussion of the definition of quality measurement and a description of the life cycle of quality measures, including the development of quality measures (across provider types); the process of endorsement of quality measures; and the process for implementing those measures. Overviews of selected examples of implementation, including the Physician Quality Reporting Initiative (PQRI) and the Reporting Hospital Quality Data for Annual Payment Update (RHQDAPU), are included. The report concludes with an overview of key technical and policy issues in quality measurement. The U.S. health care system is characterized by systemic quality shortcomings. The IOM stated in 2001 that "[c]rucial reports from disciplined review bodies document the scale and gravity of the problems. Quality problems are everywhere, affecting many patients. Between the health care we have and the care we could have lies not just a gap, but a chasm." Significant activity has been undertaken to improve the quality of care delivered in the United States over the past decade, but a number of concerning trends remain. The U.S health care system's quality problems are evidenced by a broad range of relevant quality indicators. These include high rates of medical and medication error; a high amenable mortality rate; overuse, underuse, and misuse of health care services; and a lack of, and variation in, diffusion of evidence-based guidelines. In its 1999 study, the IOM reported that between 44,000 and 98,000 people die each year because of preventable medical errors, at a cost of between $17 billion and $29 billion per year. Serious adverse medication events are estimated to occur in up to 15% of hospitalized patients, and more than 100,000 deaths are attributed annually to such reactions. A July 2008 study reports that despite spending two times more per capita than any other major industrialized country on health care, the United States has an amenable mortality rate—deaths that are amenable to health care intervention and may have been prevented by that intervention—of 110 per 100,000 (ranking 19 th out of 19 surveyed countries). With respect to the problems of overuse, misuse, and underuse of health care services, a study conducted by the Midwest Business Group on Health in 2003 found that approximately "30 percent of all direct health care outlays are the result of poor-quality care, consisting primarily of overuse, misuse and waste." Another study found that as many as 20% to 30% of patients received contraindicated care. In addition, a 2007 RAND study found that only 46.5% of children receive care recommended by evidence-based guidelines, and a similar RAND study conducted in 2003 concluded that adults receive only 55% of indicated care. According to the IOM, an average of 17 years is required for findings from randomized clinical trials to be implemented into clinical practice, and when they are, it is done so in an uneven fashion. Taken together, these findings evidence significant shortfalls in the quality of care provided in the United States. Despite the fact that most experts agree that health care quality is a serious problem deserving of attention, a precise operational definition for the concept can be difficult to identify. Although there is no single universally agreed upon definition for quality of care, or health care quality, perhaps the most commonly cited definition is the IOM's definition, as follows: "(t)he degree to which health services for individuals and populations increase the likelihood of desired health outcomes and are consistent with current professional knowledge." The 2001 IOM report "Crossing the Quality Chasm" further defines quality of care in terms of six domains: Effective . Providing services based on scientific knowledge to all who could benefit. Efficient . Avoiding waste, including waste of equipment, supplies, ideas, and energy. Equitable . Providing care that does not vary in quality because of personal characteristics. Patient-centered . Providing care that is responsive to and respectful of individual patient preferences. Safe . Avoiding injuries to patients from the care that is supposed to help them. Timely . Reducing waits and sometimes-harmful delays. Most health care quality efforts aim to improve one or more of these six domains of quality of care, and quality care is often colloquially defined as simply delivering the right care to the right person at the right time. However basic it may appear, operationalizing these six domains, and thus improving health care quality, has proven difficult. The effort to improve health care quality is operationally embodied by a wide range of quality activities. One way to consider these activities is by grouping them into one or more of the following four areas: (1) research (basic, translational, and health services); (2) quality measurement; (3) quality reporting (encompassing both increased transparency and incentive alignment); and (4) patient safety activities. Reliable and sound quality information plays a fundamental role in all of these health care quality activities, which may both use and generate such information. For those activities that rely on quality information, such as quality reporting, their effectiveness is directly dependent upon the quality of the information available. There are various types of quality information, including evidence syntheses, health technology assessments, clinical comparative effectiveness data, clinical practice guidelines, quality measure data, and medical error/near miss reports. In many cases, these different types of information are interrelated. For example, evidence syntheses are utilized as the basis for the development of clinical practice guidelines, which in many cases in turn serve as the basis for developing quality measures. Quality information may be broadly leveraged through the types of activities referenced above for a number of purposes, including to educate and inform providers about performance; for public reporting to inform consumer decision making; to create payment incentives; to inform accreditation or maintenance of certification; to inform internal quality assurance or improvement efforts; for public health surveillance efforts and activities; and to inform system-level changes to improve safety. Quality information may be fed back to inform the modification of quality measures, incentive programs, quality assurance activities, health care provider education, or the processes of delivering health care with the goal of improving quality. This report focuses specifically on quality measurement, one subset of quality activities, and will focus on the processes used to develop, endorse, select, and implement quality measures. Broadly, quality measurement focuses on assessing processes, structures, and outcomes of health care, and for this reason, quality measures are informally categorized as structural, process, or outcome measures. This model of quality measurement rests on the premise that a sound structure will support appropriate processes of care that in turn will result in good outcomes. Ideally, process measures are supported by research demonstrating a link to improved outcomes, and all measures will assess things that are under the direct control of the health care system. Structural measures assess whether "the resources and organizational arrangements are in place to deliver care," for example, staffing ratios or health information technology (HIT) implementation. Process measures assess whether the "appropriate provider activities are carried out to deliver care," for example, percentage of indicated patients receiving mammograms within a given timeframe. Finally, outcomes measures assess "the results of physician and other provider activities," for example, 30-day mortality rates post-hospitalization for pneumonia. Composite measures, which summarize performance across separate and discrete measures of quality, are a useful tool for certain end-users, such as policy makers and the general public. The Centers for Medicare and Medicaid Services (CMS) now includes several Agency for Healthcare Research and Quality (AHRQ)-developed composite measures in its Reporting Hospital Quality Data for Annual Payment Update (RHQDAPU) program (described later in this report). In addition, quality measures may be developed in order to collect patients' reports of system performance. An example of this type of measure may be found in the Consumer Assessment of Healthcare Providers and Systems (CAHPS) survey and the Hospital Consumer Assessment of Healthcare Providers and Systems (HCAHPS) survey, both funded by AHRQ. While these measures may assess the delivery of evidence- or consensus-based clinical care, they also include an evaluation of the human aspects of how that care was delivered. Quality measures may attempt to assess or evaluate one of three broader breakdowns in health care quality: (1) overuse of health care services, (2) misuse of health care services, or (3) underuse of health care services. This approach encompasses variation in care patterns as well as disparities in quality of care received.