Institutions, associations, and government agencies issue health related standards and guidelines which are widely used and recognized in the U.S. Standards are authoritative statements that articulate minimal, acceptable or excellent levels of performance or that describe expected outcomes in health care delivery, biomedical research and development, health care technology, or professional health care. Guidelines are statements of principles or procedures that assist professionals in ensuring quality in such areas as clinical practice, biomedical research, and health services. Practice guidelines assist the health care practitioner with patient care decisions about appropriate diagnostic, therapeutic, or other clinical procedures for specific clinical circumstances.

NLM collects comprehensively the following types of standards and guidelines:

• Practice guidelines
• Official U.S. national standards in health care technology, biomedical research and development, and health care
• Standards of conduct and professional competence for U.S. health care professionals
• Standards and guidelines issued by the World Health Organization

Other influential or widely recognized standards and guidelines also are collected.