Clinical practice guidelines: moving into the 21st century

Clinical practice guidelines affect every aspect of healthcare. Practitioners, third-party payors, regulatory bodies, governments, and accrediting agencies increasingly use these guidelines, which are developed by a wide variety of organizations. The majority of guidelines are based on consensus and a nonsystematic literature review, but some, including those developed by the Agency for Health Care Policy and Research, are evidence based. Both types of guidelines have distinct advantages and limitations. Consensus-based guidelines are less time consuming to develop but may lack crucial information and result in a wide variety of outcomes; whereas, the type of evidence used to develop strength-of-evidence ratings for evidence-based guidelines may result in ambiguous recommendations and cause ethical concerns. Outcomes research on the use of guidelines and issues related to their timeliness need to be addressed. Studies that include a wide variety of outcome indicators and care variables and contributions of clinicians are needed to develop practice guidelines that are clinically useful and improve patient care.