Quality assurance aims to monitor nursing activities to ensure a high level of patient care. It involves defining nursing standards and using them to evaluate and improve care. Approaches include credentialing, licensure, accreditation and certification of individuals and organizations. Quality is assessed using peer review, standards, and audits to compare care to accepted criteria. The American Nurses Association model identifies values, sets structure/process/outcome standards, selects measurements, interprets results, identifies actions, chooses solutions, and reevaluates to continually improve nursing quality.