There are two key questions to answer in guideline evaluation. In addition to these questions, there are some practical issues that need to be considered. Guidelines will be appropriate in some settings but not in others, and may require resources for implementation that aren't available to you. The key issue in evaluation is the process used to develop the guideline. Different methods of guideline development vary dramatically in their reliability and validity.
Guidelines often lack adequate documentation.
Most guidelines without clearly stated development processes fall into two general categories. As might be expected, there is no way to diminish the contribution of the individual's biases about care, and the resulting guideline may be as likely to recommend care that is harmful as care that is helpful. This is the most commonly used method of guideline development. To understand how this process works, it may be helpful to use a more descriptive definition - global subjective agreement of experts. The advantage is its fast and inexpensive when compared to the more rigorous methods of guideline development.