In this section of the EBM Express course, we'll be introducing the concept of critical appraisal. Our learning objectives for this section are to understand the role of critical appraisal in evidence-based medicine and share some basic appraisal questions to be asked when reading an article or study. In earlier sections of EBM Express, we learned that evidence-based medicine has a process. This process is frequently visualized as a cycle of five A's. The five stage evidence cycle includes assess, ask, acquire, appraise, and apply. The evidence cycle begins with the clinician taking time to assess the clinical situation and define a problem. They then ask a question related to the clinical problem. This is where they frequently start to seek help from an information professional. Following ask comes acquire where the evidence is found through searching the medical literature and database resources for appropriate studies. Once the evidence is in hand, the next stage is appraise. The studies that were found through searching will attempt to answer the underlying truth of the question. However, even the best research studies almost never exactly represent the real world. Critical appraisal will help identify the flaws of the study, exposing the risk of bias and design errors. This critical appraisal step is vital before a clinician can move on to actually applying the evidence to their patient or situation. As a reminder, the process of EBM is iterative. At any stage, you may find it necessary to revise what you are seeking to best meet the patients clinical needs or preferences. You may need to go back a step or two to start the cycle over. And this may happen many times. Now that we understand how critical appraisal fits within evidence-based medicine, how is it actually done? We always want to start by asking some simple questions. Ask questions related to the study aims and conclusions like have the study aims been clearly stated? Are the conclusions logical? Have they included limitations? Can the results be extrapolated to other populations? Continue by asking questions related to the methods. Have the methods been described in detail? Does the sample accurately reflect the population? Have exclusions been stated? Is the control group easily identified? And are enough details included so that the results could be replicated. If a study fails several of these basic questions about the study aims, methods, and conclusions, you may not want to use it. If however the study passes these types of basic questions, you can move on to considering other factors and appraising the article in more depth. Beyond initial questions, there are many factors to consider when doing critical appraisal. Some of the factors that we'll be reviewing in this course are bias, validity, reliability, and statistical analysis. There are also many tests, standards, tools, and other resources to help you do critical appraisal. Some are free and others require a subscription. A few notable sources of critical appraisal tools are the center for evidence-based medicine, the critical appraisal skills program, JAMA evidence, which includes the users guides to the medical literature, and squire. These are just some of the many resources available. In summary, critical appraisal is a vital piece of evidence-based medicine. Evidence that is acquired cannot be applied without first appraising it. Start your critical appraisal by asking basic questions. You can then move on to consider other factors like bias, validity, reliability, and statistical analysis. Fortunately, there are many tools and resources to help you do critical appraisal. This section of EBM Express has only been a brief introduction to critical appraisal as a part of the EBM cycle. Other concepts like bias, validity, reliability, and statistical analysis will be introduced in other sections of this course. Specific tools and measures used in appraising studies will also be introduced in the course.