Steps in the Process of Evidence-Based Practice
Step 4: Making the Decision
Finally, the time will come to combine clinical expertise, the patient's perspective, and the available scientific evidence in making a specific clinical decision with a specific patient. In some instances, evidence-based clinical guidelines will already have been developed on topics related to your particular question. There are at least three important factors to keep in mind when considering whether and to what extent to follow the guidance contained in such documents.
The first is relevance of the guideline to your specific clinical question (see
framing the clinical question). If the brain-injured patient whose care prompted your question is a member of a cultural or linguistic minority, for example, how useful are brain-injury guidelines that exclude or make no specific mention of culturally or linguistically diverse populations? If you are treating an autistic teenager, of what relevance are guidelines developed primarily on the basis of evidence from younger children? Once again, the expertise and experience of the individual clinician is an absolutely essential part of evidence-based practice.
The second consideration is the extent to which clinical practice guidelines are truly evidenced-based. Many guidelines are produced via an expert consensus process or other non-systematic approaches. While expert consensus can certainly be a valuable source of information, the conclusions are particularly vulnerable to the biases held by the "experts", and history is full of examples of such conclusions being simply wrong.
If a guideline is truly evidence-based, the methodology by which evidence was identified and evaluated should be transparent. Unfortunately, transparency in itself is not a guarantee of quality. It can be a challenge for clinicians to determine what is and is not a high quality evidence-based practice guideline. Systems for evaluating practice guidelines have been developed and can be useful tools to help determine whether a guideline should be applied. The most prominent of these tools is the
Appraisal of Guidelines Research and Evaluation II (AGREE II) framework. AGREE II was developed by the European Union and has subsequently been endorsed by the US Agency for Health Research and Quality (AHRQ).
The third factor to consider is who wrote and published the guideline. While many guidelines are produced by academic institutions and interdisciplinary collaborations, others are produced by advocacy groups or payors. It is important to consider who produced the guidelines and to what extent they would likely be affected by positive or negative recommendations. However, guidelines emanating from a "trusted" source are no more guaranteed to be of high quality than are guidelines coming from a less objective source guaranteed to be flawed. Application of the AGREE II or other objective criteria should be the final determinant of the guideline's quality.
Where to Find Evidence-Based Practice Guidelines
When guidelines are either inapplicable or non-existent, then the clinician must rely on the evidence identified and assessed in the previous steps (
Finding the Evidence and
Assessing the Evidence). There typically is no magic formula for determining how much evidence is "enough." Factors such as patient preference, cost effectiveness, potential for harm and availability of alternative treatments all come into play in ultimately making the treatment decision.