A substantial amount of research exists demonstrating that health care frequently fails to meet the current standards of quality care. Errors, suboptimal management or control of disease, and overutilization or underutilization of services are more likely to occur when high quality evidence-based health care is not provided. In a quality improvement framework that includes measuring, influencing, and improving quality, public reporting (making quality, safety, or performance data publicly available) is categorized as a means of influencing quality by providing incentives for change. This report focuses on how the public reporting of health care quality information may provide incentives for quality improvement that ultimately produce higher quality care. It is part of the Closing the Quality Gap: Revisiting the State of the Science series, which examines the role of several interventions in promoting quality health care. Quality might be influenced by the different incentives public reports create for different people and organizations. The incentives may be for the consumers of health care, including patients, families, or advocates who act on the behalf of patients, or for other purchasers of health care services, such as employers, who select the options available to their employees. Public reporting can also provide incentives for the individuals and organizations that provide or arrange care, including individual clinicians, hospitals, long-term facilities or services, and health plans. Patients are motivated by the desire to maximize the benefits they derive from health care by obtaining the highest quality of care available. Individual clinicians, hospitals, and other organizations that provide or arrange health care want to attract new patients or members and avoid losing existing ones. They may also be motivated by concern about their reputation among their peers or by professional and organizational commitments to providing high-quality care. This report was designed to update the last published systematic review, given the significant changes that have occurred in the scope and nature of public reporting. Medicare has substantially expanded its public reporting program, health data from many more sources are now available with minimal restrictions, new technologies allow aggregating data from consumer feedback sites, and applications have been built to help customize and simplify the combination of data from multiple sources. These trends and continuing commitments to transparency and patient-centered health care are likely to contribute to substantial increases in the amount of publicly available data on health care quality. The scope of this review was determined by a definition designed to situate public reporting in the context of quality improvement, the theme of the Closing the Quality Gap: Revisiting the State of the Science series. Given the resources devoted to public reporting and the desire to synthesize existing research knowledge to inform future public reporting efforts, the objectives of this systematic review were: To determine the effectiveness of public reporting as a quality improvement strategy by evaluating the evidence available about whether public reporting results in improvements in health care delivery and patient outcomes (Key Question 1) and evidence of harms resulting from public reporting (Key Question 2); To determine whether public reporting leads to changes in health care delivery or changes in patients' or purchasers' behaviors (intermediate outcomes) that may contribute to improved quality of care (Key Questions 3 and 4); To identify characteristics of public reports and contextual factors that can increase or decrease the impact of public reporting (Key Questions 5 and 6).