This is the first in a series of four articles on issues in the development and use of clinical guidelines

Over the past decade, clinical guidelines have increasingly become a familiar part of clinical practice. Every day, clinical decisions at the bedside, rules of operation at hospitals and clinics, and health spending by governments and insurers are being influenced by guidelines. As defined by the Institute of Medicine, clinical guidelines are “systematically developed statements to assist practitioner and patient decisions about appropriate health care for specific clinical circumstances.”1 They may offer concise instructions on which diagnostic or screening tests to order, how to provide medical or surgical services, how long patients should stay in hospital, or other details of clinical practice

The broad interest in clinical guidelines that is stretching across Europe, North America, Australia, New Zealand, and Africa (box) has its origin in issues that most healthcare systems face: rising healthcare costs, fueled by increased demand for care, more expensive technologies, and an ageing population; variations in service delivery among providers, hospitals, and geographical regions and the presumption that at least some of this variation stems from inappropriate care, either overuse or underuse of services; and the intrinsic desire of healthcare professionals to offer, and of patients to receive, the best care possible. Clinicians, policy makers, and payers see guidelines as a tool for making care more consistent and efficient and for closing the gap between what clinicians do and what scientific evidence supports.

As guidelines diffuse into medicine, there are important lessons to learn from the firsthand experience of those who develop, evaluate, and use them.3 This article, the first of a four part series to reflect on these lessons, examines the potential benefits, limitations, and harms of clinical guidelines. Future articles will review lessons learned …