The care that patients receive too often depends on where they live, their race, or their physician. Large variations have been found in rates of hysterectomy, mammography, A1C testing, hip replacement, spinal surgery, and hospital admission that cannot be explained by differences in age or other demographic factors.^1–3 Decisions often are driven by geographic factors, local opinion leaders, reimbursement, and local customary practices. In addition, we are increasingly recognizing that errors of omission and commission are too common in our health care system.⁴ With an increasing number of tests, drugs, and treatments to juggle for each patient, relying on the memory of individual physicians to make the best possible decisions is no longer adequate. Meanwhile, Americans spent $6,102 per person on health care in 2004—approximately twice as much as Denmark, Canada, Austria, the Netherlands, and Sweden—yet had a lower life expectancy at birth than persons in all of those countries.⁵

Practice guidelines have been proposed as a solution to inappropriate variations in care, medical errors, high costs, and poor-quality health care. The airline industry has dramatically reduced its error rate (as measured by major crashes) by requiring checklists, standard protocols, and the aviation equivalent of practice guidelines to be used by pilots, who initially were as reluctant as physicians to adopt such procedures. Would you be comfortable getting on a plane if it was left to the pilot’s memory and discretion to check the engines and flaps, and to make sure the plane had enough fuel?

Nevertheless, guidelines sometimes are criticized by those who call them “cookbook medicine” and decry their perceived interference with “the art of medicine.” Sometimes this criticism is based on false notions of what is correct; these ideas often are formed on the basis of faulty evidence or are contradicted by recent research literature. Sometimes the criticism is based on a lack of understanding of what makes a well-designed guideline. On the other hand, sometimes the criticism is valid; a guideline that is too rigid, that is not based on a careful review of the evidence, or that fails to communicate clearly and effectively is unlikely to improve the quality of care, and it may even worsen it.

What makes a well-designed guideline? The best guidelines share several characteristics: they begin with a comprehensive review of the literature; they carefully assess the quality of the literature to identify the best studies; they base their recommendations on the best studies; and they tell us the strength of the evidence that supports each key clinical recommendation. In other words, they are founded on the principles of evidence-based medicine, which strives to make decisions on the best available information—“best” implying that the evidence is graded, so that one has a sense of what is good evidence and what is not, and “available” implying that the literature search is comprehensive. Transparency is the key: readers should know why each recommendation is made and whether it represents opinion, theory, or fact. Finally, guidelines should be independent of industry support (an all-too-common occurrence⁶) and should clearly identify any potential conflicts of interest of the authors. Ideally, guideline authors should have no conflicts of interest, which can diminish the quality and validity of the guideline.⁷

This month in American Family Physician, we will begin giving you more information about the practice guidelines that we summarize.⁸ We will tell you in an easy-to-read box who created the guideline; where you can find it online; whether the authors performed a comprehensive, well-described search of the literature; whether they rated the strength of clinical recommendations; and whether there were any potential conflicts of interest. We think this will make it easier for you to choose the best guidelines for your practice.

editor’s note: Dr. Ebell is deputy editor for evidence-based medicine for American Family Physician. Dr. Siwek is editor of AFP.