Medical Research Essentials PDF

# INTRODUCTION ## WHY EVIDENCE-BASED MEDICINE? Evidence-based medicine is the conscientious, explicit, and judicious use of the best current evidence in making decisions about the care of individual patients. - David L. Sackett, et al., BMJ. 1996;312:71 Evidence-based medicine (EBM) is an ongoi...

# INTRODUCTION ## WHY EVIDENCE-BASED MEDICINE? Evidence-based medicine is the conscientious, explicit, and judicious use of the best current evidence in making decisions about the care of individual patients. - David L. Sackett, et al., BMJ. 1996;312:71 Evidence-based medicine (EBM) is an ongoing and burgeoning field that has now become the norm in today's practice of medicine. It is defined as the union of individual clinical expertise with the most current research evidence and patient values. It involves a systematic approach to clinical problems aimed at identifying strategies that work and eliminating those that do not work, are harmful, or are proven to be not beneficial based on research evidence. EBM promotes critical thinking. It demands that the effectiveness of clinical interventions, the accuracy and precision of diagnostic tests, and the power of prognostic markers be scrutinized and their usefulness proven. It requires clinicians to be open-minded and look for and try new methods that are scientifically proven to be effective and to discard methods shown to be ineffective or harmful. Given the heavy emphasis on EBM, it is therefore critical to understand the elements of this in order to use it in practice. The “evidence” points to what is the best practice available today, and that may change within days to years. Applying the knowledge gained from large clinical trials to patient care promotes consistency of treatment and optimal outcomes, helps establish national standards of patient care, and sets criteria to measure and reward performance-based medical practice. Implementing the principles of EBM, which rely on the rules of evidence and research, requires a commitment from medical schools, local health and medical licensing departments, physicians, pharmacists, professional associations, and managed care organizations. This kind of commitment can come in various forms such as emphasis on research projects, journal clubs, didactics, team rounds, and finally individualized assessments. The elements of EBM are summarized in five simple steps: 1. **Asking a focused question:** One of the most difficult steps in practicing medicine in general is translating a patient clinical problem into a well-structured question. Many questions can arise when confronted with a clinical scenario. However, one must develop skills to convert this information into a focused clinical question that is relevant to the problem at hand. The next step is how to phrase that question in order to facilitate the search. A useful framework was developed by Sackett et al’ in which they proposed that a good clinical question should address four main elements abbreviated as PICO: the patient or population at hand (P), the intervention or exposure (I), the comparison (C), and the clinical outcomes (O) that are associated with it. All these elements comprise the PICO method for asking a clinical question that proves to be helpful in not only asking a clinical question but also appraising the literature. An additional element can be added to this framework to account for time (T). An example of implanting this method is as follows: Imagine that a 50-year-old male patient with no risk factors comes to see you in your clinic and asks you whether he should take aspirin to prevent cardiovascular disease. Following the PICOT method: * P: A healthy adult * I: Aspirin * C: No aspirin * O: Cardiovascular disease * T: In 5 years Therefore, the question you should ask would be: In an otherwise healthy man with no risk factors or medical conditions, what is the benefit of taking aspirin versus no aspirin in preventing cardiovascular disease in 5 years? This question, now focused, can be placed in the EBM paradigm in order to provide the patient with the best care. The PICOT method is described in detail in Chapter 2. 2. **Finding the evidence behind that question**: Typically, this is done by searching the literature by way of national databases, guidelines, and journal articles. Combining the current accepted and tested parameters with one’s experience and expertise is the most effective method for obtaining the best approach for one’s patients. The ability to search these databases effectively is yet an important aspect of EBM, since it is important to be able to extract the relevant pieces of data that are pertinent to your question. Basic search principles include: * Convert a clinical problem into a question (achieved in the first step in EBM). * Generate appropriate keywords. * Choose a bibliographic database. There are numerous online databases, including PubMed, MEDLINE, EMBASE, and Cochrane. The Cochrane library includes a database of systematic reviews, controlled trials, and abstracts, which is updated quarterly by an international initiative and available via the internet. * Conduct the search. At the basic level, an efficient method is to combine individual words or terms using the Boolean operators “AND” and “OR”. If you are combining two terms, AND allows only articles containing both terms to be retrieved, and OR allows articles containing either term to be retrieved. Sometimes results of a search can retrieve an innumerable amount of hits, which can be further queried based on one’s own preferences such as time period (2000-2013) and types of study (randomized controlled trials only). 3. **Appraising the evidence**: Although there is a wealth of research articles available, the quality of these is variable. After the appropriate information and evidence have been compiled, the next step is to test it for validity, applicability, and clinical relevance. This is vital because each clinical scenario is different and unique and requires delicate fine-tuning to make sure that it is applicable and sound for that clinical scenario and especially for that patient’s own wishes. Several tools for appraising research articles are available, for example the tools developed by the Critical Appraisal Skills Programme (CASP), Oxford, United Kingdom. These include tools for appraising randomized controlled trials, systematic reviews, case-control studies, and cohort studies (this is also discussed further in Chapter 2). Additional ways to appraise the evidence also take the form of "levels of evidence" and "grading the strength of recommendations." 4. **Applying the evidence**: The first step is to determine whether this evidence can be applied in clinical practice. Next one should apply their own expertise to the pertinent evidence and guide the patient in making an informed decision using the available data. Research evidence includes systematic observations from the laboratory, preliminary pathophysiological studies, and more advanced applied clinical research, such as randomized controlled trials. This decision should also take into account costs and the availability of that particular treatment in practice. 5. **Evaluating performance**: After the decision has been made, the last and final step rests in evaluating whether the decision was the most appropriate. Evidence-based medicine therefore aids in improving the quality of care, patient access, treatment outcomes, appropriateness of care, efficiency and effectiveness, and cost containment by improving the cost-to-benefit ratio. Therefore, it is essential for all clinicians to develop these skills. Staying “current” and up to date on current recommendations and guidelines remains a challenge. It is especially not easy for medical students and residents, given their long work hours and study schedule, to find time to become a part of this paradigm. Although a majority of programs recently have focused on EBM as part of research, it remains a field heavily emphasized primarily in competitive programs. The purpose of this book is to provide a research guide to medical students and residents to help them understand the elements of research in a practical way and to aid them in translating their own questions and clinical problems into solid research projects. Training physicians who are adept at evaluating the literature with an EBM perspective would allow for providing the best medical care at the lowest cost and achieving optimal outcomes. # Figure 1.1 The image depicts a Venn diagram with the following elements: * Individual clinical expertise * Patient values * Research evidence * EBM The image is labelled "Evidence-based medicine (EBM) Venn diagram. EBM is defined as the union of individual clinical expertise with the most current research evidence and patient values." # Figure 1.2 The image is a diagram that depicts the 5 steps of evidence-based medicine (EBM). It is labelled "Approach to evidence-based medicine (EBM). EBM involves five main steps: (1) asking a focused question through the PICO method (*explained in detail in Chapter 2); (2) finding the evidence behind that question via a literature search; (3) appraising the evidence and testing it for validity, applicability, and clinical relevance; (4) applying the evidence in the form of making a decision; and (5) evaluating performance to patient care."