Abstract
This article provides an introductory step-by-step process to appraise clinical practice guidelines. The authors introduce these principles using a systematic approach and case-based format. The process of assessing the validity of clinical practice guidelines, determining their importance, and applying them to an individual patient is reviewed. The concepts of study population homogeneity, equal treatment, and study completeness are discussed to help physicians determine the validity of clinical practice guidelines. Finally, information that is learned from the previously mentioned steps is applied to patient care. Study generalizability and the role of patient values, expectations, and concerns are also addressed. The skills learned from appraising clinical practice guidelines in the manner outlined provides a solid basis for life-long learning and improved patient care.
Physicians, who use their clinical skills to treat patients and diagnose diseases on a daily basis, must be informed of current clinical practice guidelines and standards of care in order to provide their patients with the best care possible. However, because such guidelines may have different recommendations depending on who wrote or sponsored the guideline, they may not be applicable to any given patient. Therefore, physicians must remain cognizant of the rationale used to develop such guidelines—in particular the evidence base used—while at the same time assessing the guidelines' validity and applicability. One such tool to develop clinicians' skills in evaluating guidelines is evidence-based medicine (EBM).
In this article, we introduce a strategy for busy physicians, physician residents, and medical students to critically assess clinical practice guidelines. In-depth details of research methods are beyond the scope of this introductory series on EBM. Readers are encouraged to seek further training on these topics with supplemental learning opportunities and continuing medical education. Finally, the clinical scenario described has been simplified to provide readers with an illustrative example for the general concepts introduced.
The initial step required for a critical review of clinical practice guidelines involves evaluating the document's stated purpose (eg, diagnosis, prevention, symptom control). Secondarily, physicians practicing EBM are concerned with evaluating how closely the guideline's purpose is aligned with a particular patient's needs (
Figure 1).
Guidelines are valuable insofar as they provide clear and practical recommendations for a clinical challenge. A guideline, to prove relevant, must be supported by evidence that assesses the risks, benefits, and costs of the proposed intervention. A guideline should also explain how its recommendations can be implemented, regularly reviewed, and updated to ensure accurate and up-to-date information is provided.
There are a number of items to take into consideration when appraising a clinical practice guideline. Greenhalgh
1 suggests 10 questions to use when reviewing a guideline (
Figure 2). For example, Greenhalgh asks, “Did the preparation and publication of this guideline involve a significant conflict of interest?” If the guideline developers received financial support from a pharmaceutical company that manufactures a medication recommended in the guideline, those guideline authors may be unconsciously (or consciously) biased with their specified recommendations. Similar to how authors of articles published in medical journals are required to disclose financial relationships,
2,3 members of guideline development teams should divulge any special interests they have related to the topic of the clinical practice guideline.
Although conflict-of-interest statements are often absent from guidelines,
4 a good guideline will disclose any potential bias so physicians can better determine the strength of the guidelines. If a physician finds that there is a significant conflict of interest in either the preparation or publication of the guideline, he or she should begin a new search for recommendations.
Additional questions that might be asked by a physician practicing EBM include the following:
A guideline's generalizability is directly related to its inclusion and exclusion criteria (eg, guidelines based on more stringent criteria are less generalizable to a population).
5 In addition, applicability of clinical practice guidelines must consider the burden of disease, the patient's values and unique circumstances, and any practical barriers to guideline implementation. If the burden of disease is very low, any intervention's risk-to-benefit ratio becomes less advantageous to the patient.
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Patients and physicians must work together to ensure both parties are making informed decisions. Insurance restrictions, availability of interventions, and patient factors and limitations (eg, financial, logistic) are common practical barriers to guideline implementation. All of these factors must be addressed to ensure a guideline is applicable to any given patient (
Figure 5). However, these factors do not affect the basic evidence or scientific validity of a guideline.
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Although most clinicians are already incorporating EBM principles in their practices, often instinctively, some physicians may require a more organized approach to integrating this relatively new model of self-education. Improved comfort levels and true expertise in the practice of EBM are the result of additional education, repetition, and self-assessment. The principles of EBM allow physicians to stay informed while also improving the quality of the information communicated to patients during patient encounters. The systematic approach that is used to appraise clinical practice guidelines is but one step in practicing EBM. Remember, the goal is always to provide the best care possible to patients—using one's clinical expertise to address patient values and expectations for treatment.