Clinical practice guidelines have been a fundamental component of medical practice since one physician first asked another how to manage a patient. A clinical practice guideline is formally defined as a preformed recommendation made for the purpose of influencing a decision about a health intervention.1 In practice, however, journal articles, editorials, algorithms, care maps, computerized reminders, textbook chapters, and advice from consultants are all clinical practice guidelines in the general form “if x, then y” on some clinical question.
The terminology defining these decision rules is not standard. Physicians will find the terms practice policy, clinical guideline, practice parameter, clinical pathway, standard, algorithm, and many others used synonymously. This article uses the term clinical practice guideline.
The recent surge of interest in clinical practice guidelines has several parents. First, medical history is littered with clinical practice guidelines that have been fatally incorrect, leading to interest in methods that promise better validity and reliability. Second, the physician's ability to keep up with the medical literature erodes with each year's burden of (literally) millions of medical articles published worldwide, leading to interest in methods that make sense out of the vast amount of information on a given clinical topic. Third, costly and unexplained variability in medical practice, documented everywhere one looks, leads to interest in developing more accountable approaches for those conditions for which the greatest variations in practice or cost occur (this parent is strongly driven by the shift to more managed care). Fourth, growing demand from patients for greater participation in medical decisions leads to searching for a process in which benefits and harms are linked to outcomes explicitly in terms that patients can understand. Driven by these four parent concerns, methods used to develop clinical practice guidelines have evolved rapidly in recent years. It is important to emphasize, however, that the modern “clinical practice guidelines movement” is too young to have demonstrated success in addressing any of the four concerns, although relevant research attempting to do so is under way in many centers.
Beyond addressing the above concerns, clinical practice guidelines are used for many purposes, some of them competing. Well-formulated clinical practice guidelines can be used positively not only to guide practice, but also for education, quality assurance and improvement, and cost accountability, ends with which most physicians would agree. On the negative side, guidelines are also used in malpractice actions to justify or attack care provided in specific cases with adverse outcomes, and are used by groups of physicians in attempts to protect clinical turf. Poorly constructed clinical practice guidelines are justifiably attacked when used in any setting, but physicians who assist in developing well-designed evidence-based guidelines must be prepared to find the products used in all kinds of appropriate and inappropriate ways. Attentiveness to the integrity of the process used to generate clinical practice guidelines must be matched with vigilance to guard against inappropriate use.
This article presents an overview of methods used to construct clinical guidelines, discusses an extended example—screening for prostate cancer—and concludes with a review of the use of clinical guidelines in practice and education.