Clinicians and health systems are facing widespread challenges, including changes in care delivery, escalating health care costs, and the need to keep up with rapid scientific discovery. Reorganizing U.S. health care and changing its practices to render better, more affordable care requires transformation in how health systems generate and apply knowledge. The "rapid-learning health system"-posited as a conceptual strategy to spur such transformation-leverages recent developments in health information technology and a growing health data infrastructure to access and apply evidence in real time, while simultaneously drawing knowledge from real-world care-delivery processes to promote innovation and health system change on the basis of rigorous research. This article describes an evolving learning health system at Group Health Cooperative, the 6 phases characterizing its approach, and examples of organization-wide applications. This practical model promotes bidirectional discovery and an open mind at the system level, resulting in willingness to make changes on the basis of evidence that is both scientifically sound and practice-based. Rapid learning must be valued as a health system property to realize its full potential for knowledge generation and application.

Update of the 1996 U.S. Preventive Services Task Force (USPSTF) recommendation statement on counseling to prevent household and recreational injuries, including falls.

Viscosupplementation, the intra-articular injection of hyaluronic acid, is widely used for symptomatic knee osteoarthritis.

Sleep plays a critical role in maintaining health and well-being; however, patients who are hospitalized are frequently exposed to noise that can disrupt sleep. Efforts to attenuate hospital noise have been limited by incomplete information on the interaction between sounds and sleep physiology.

Little is known about the influence of contextual factors on a physician's likelihood to prescribe antimicrobials for febrile respiratory illness (FRI). Context includes epidemiologic context (for example, a pandemic period) and personal context (for example, recent exposure to other patients with FRI).

Hemoglobin A1c (HbA1c) levels are known to be consistently higher in black persons than in white persons at any given glycemic level. Whether the optimal diagnostic threshold of HbA1c should differ between blacks and whites is unclear.

Update of the 2004 U.S. Preventive Services Task Force (USPSTF) recommendation statement on screening for coronary heart disease (CHD).

Insights from systematic reviews can help new studies better meet the priorities and needs of patients and communities. However, systematic reviews unfortunately have not yet achieved this position to direct and guide new research studies. The Agency for Healthcare Research and Quality's Evidence-based Practice Center Program uses systematic reviews to identify gaps in current evidence and has developed a systematic process of prioritizing these gaps with stakeholder input into clearly defined "future research needs." Eight Evidence-based Practice Centers began to apply this effort in 2010 to various clinical and policy topics. Gaps that prevented systematic reviewers from answering central questions of the review may include insufficient studies on subpopulations, insufficient studies with appropriate comparators, lack of appropriate outcomes measured, and methods problems. Stakeholder panels, consisting of advocacy groups, patients, researchers, clinicians, funders, and policymakers, help refine the gaps through multiple conference calls and prioritization exercises. Each report highlights a focused set of 4 to 15 high-priority needs with an accompanying description of possible considerations for study design. Identification of high-priority research needs could potentially speed the development and implementation of high-priority, stakeholder-engaged research.