Evidence-Based Medicine PDF

Steps of evidence-based medicine  Definition  Evidence-based medicine (EBM) requires the integration of the best research evidence with our clinical expertise and our patient's unique values. By best research evidence clinically relevant research A-accuracy and precision of diagnost...

Steps of evidence-based medicine  Definition  Evidence-based medicine (EBM) requires the integration of the best research evidence with our clinical expertise and our patient's unique values. By best research evidence clinically relevant research A-accuracy and precision of diagnostic tests (including the clinical examination), B-the power of prognostic markers C-the efficacy and safety of therapeutic, rehabilitative, and preventive strategies.  Definition  By clinical expertise  our clinical skills and past experience to rapidly identify each patient's unique health state, his or her individual risks and benefits of potential interventions/exposures/diagnostic tests  By patient values  mean the unique preferences, concerns, and expectations that each patient brings to a clinical encounter and integrated into shared clinical decisions; by patient circumstances, we mean the patient's individual clinical state. The key steps in Evidence-Based Medicine: five steps  Step 1 : converting the need for information (about prevention, diagnosis, prognosis, etc.) into an answerable question.  Step 2 :tracking down the best evidence to answer that question.  Step 3 : critically appraising that evidence for its validity (closeness to the truth), impact (size of the effect), and applicability (usefulness in our clinical practice).  Step 4 : integrating the critical appraisal with our clinical expertise and with our patient's unique values, and circumstances.  Step 5 : evaluating our effectiveness and efficiency in executing steps 1 to 4 and seeking ways to improve them The 5 Steps of Evidence Medicine  Well-built clinical questions  “Background” questions Ask for general knowledge about a condition, test, or treatment  Have two essential components: 1.A question root (who, what, where, when, how, why) 2. A disorder, test, treatment, or other aspect of health care.  Examples:  “How does heart failure cause pleural effusions?”  “What causes swine flu?”  Well-built clinical questions  “Foreground” questions Ask for specific knowledge to inform clinical decisions or actions  Have four essential components: 1.P: Patient, population, or problem. 2. I:Intervention, exposure, test 3. C: Comparison intervention, exposure, test, if relevant. 4. O: Outcomes of clinical importance, including time, when relevant.  Well-built clinical questions  Example: “In adults with heart failure and reduced systolic function, would adding the implantation of an electronic resynchronization device to standard therapy reduce morbidity or mortality enough over 3 to 5 years to be worth the potential additional harmful effects and costs?”  a. A question root (who, what, when, where, how, why) with a verb.  b. An aspect of the condition of interest.  Note that the house officers' questions concern specific knowledge that could directly inform one or more “foreground” clinical decisions they face with this patient  1. Asking the right question  Getting the question right  The question should be clear and focused In term of PICO  Patient, Intervention, Comparison and Outcome.  Here is an example of a clearly focused question:  Does aspirin reduce your risk of death after a heart attack? Patient :Adults who have suffered a heart attack in the past month. Intervention : Aspirin. Comparison: No treatment/placebo. Outcome: Death.  1. Asking the right question  Here is an example of a question that is too broad and not focused enough:  Do antibiotics help children with colds? Patient :Children with colds How old? – All children from any age. What do we mean by a ‘cold’? With a temperature or a runny nose? With a proven diagnosis of a bacterial infection? Intervention :Antibiotics – Which antibiotics? All of them? Comparison : What comparator? A different type of antibiotic? A placebo? Nothing? Outcome : What does “help” mean? Are we interested in symptoms/signs/quality of life/days off school?  1. Asking the right question  Here is an example of a question that is too focused  Does amoxycillin reduce facial pain in teenagers (13-18) with microbiologically-proven maxillary sinusitis? Patient : It is very unusual to find teenagers with maxillary sinusitis who have had a culture taken to prove that they have a bacterial cause. Not likely day-to-day clinical practice situation. Intervention : Amoxycillin – It isn’t unreasonable to consider this antibiotic but it might be more helpful to look for other antibiotics as well. Comparison :What comparator? A different type of antibiotic? A placebo? Outcome: Reduction of facial pain – A study will only find a reduction in facial pain Is this the most important outcome? Should you be looking for a set of outcomes including the adverse effects of treatment.  2. Searching for evidence  Finding the evidence to answer your focused question. Usually you will be looking for a particular type of paper;. This will usually, but not always, be a randomized controlled trial (RCT).  There are several large databases  PubMed ,it contains over 23 million articles. Some articles are simple case reports and some are observational studies  Some are trials testing a drug or intervention against an alternative treatment or placebo.Only some of these are controlled trials and only some of those are randomized controlled trials.Some articles bring together several studies to increase the precision and power of results and reduce bias (systematic reviews are one example of these). 3. Appraising the evidence  Unfortunately, you cannot rely 100% on papers written in even the most prestigious journals.  Different types of studies reported in papers have different weaknesses and strengths. You need to know how to separate what is significant from what is not. it is important to be able to critically appraise.  there are three key questions to ask when looking at a paper:  Is the study valid (in other words, are the results of the study reliable because it was done in the best possible way),  what are the results of the study, will the results help me in looking after my patients. 3. Appraising the evidence  In general larger studies are preferred to smaller ones (less likely to be the result of chance). But this is just one aspect of a paper. the Methods section is key to understanding how the study was done.  At the end of the appraisal process you will have a better appreciation of how strong the evidence is. You will know whether or not you should apply it to your patient.  4. Acting on the evidence  If you have examined all the relevant up-to-date evidence that is relevant to your focused clinical question.  Don’t get too comfortable, new evidence comes along all the time and the answer may change quickly.  You should be able to explain to your patient the overall balance of evidence considering both the benefits and harms of treatment and assist the patient make a choice in what is called the shared decision-making process.  Evidence-based practice (EBP)  Evidence-based practice (EBP) is a life-long learning technique that may help healthcare practitioners continue to improve practice methods to patient care.  These steps are similar to principles of the continuous quality improvement (CQI) cycle.  The CQI cycle typically begins with an identified need and a desire for improvement. The next steps include a search for the most appropriate information/solution, evaluation, application of the appropriate information/solution to the situation, monitoring the effects of implementation practices to make sure that an improvement has been made, then incorporating this information into regular practice.  Facilitating Evidence Based Practice  clinicians must have readily available, relevant, and concisely summarized evidence.  Clinicians may benefit from examples of reasoning, strategies, and resources to integrate evidence.  Therefore, everyone from practitioners to employers has a role in increasing EBP and transferring knowledge for practice.  A critical part of the process is actual implementation of EBP at the point of care. many clinician barriers, including lack of time, resources, or training to locate and appraise research studies. Facilitating Evidence Based Practice  Implementing EBP has become a priority in the health care professions due to: Changes in how health care is administered (e.g., increasing costs, reduced staffing, managed care systems, and shorter hospital stays)  Occupational therapy associations and organizations have responded by creating new resources and learning materials for EBP, such as OTseeker (www.otseeker.com), an online database of systematic reviews, and randomized controlled trials.  Clinicians may benefit from updated strategies and efficiently integrate evidence into daily practice. Facilitating Evidence Based Practice  Patient diagnosed with a rare disorder, Experienced clinicians tend to ask foreground questions, specific questions that affect treatment ,not broad question  The most efficient method of answering foreground questions is to find a relevant systematic review (SR) or meta- analysis.  SRs not only answer relevant clinical questions but are also of high quality.  Formulating a good clinical question depends on the purpose behind the question. Facilitating Evidence Based Practice  Systematic Reviews SRs refer to “an extensive, systematic process of identifying, appraising, and summarizing all research on the review topic” if contain a quantitative synthesis of study results, such as in the case of a meta-analysis.  Practice guidelines which often incorporate SRs. A practice guideline can be viewed as an “amalgam of clinical experience, expert opinion, and research evidence ” and can be helpful to the busy clinician by distilling evidence into practice recommendations.  critically appraised topics and critically appraised papers, are brief summaries and appraisals of a specific question or study. Facilitating Evidence Based Practice  EBP and clinical guidelines are based on a research hierarchy in which articles that have high levels of internal validity are most important  For example, randomized controlled trials are rated as providing the highest levels of evidence because they have high internal validity as a result of their design, randomization, existence of a control group, and tight control of the intervention.  To integrate evidence into practice, clinicians should determine whether the findings are clinically useful by differentiating between statistical significance and clinical significance. Facilitating Evidence Based Practice  However, a closer examination of the study may reveal that the new intervention requires expensive equipment.  Clinicians may form journal clubs, contact nearby research groups and online forums to learn more about evaluating research.  If a new intervention is easier to implement but does not adequately improve patient functional outcomes, then clinicians may want to return to the standard intervention.  Globally, an ongoing systematic scan of the research is needed to address the critical gaps in the knowledge base.  Using clinical experts to promote how to use evidence can help bridge the divide between evidence and practice.  Central issues in clinical work, where clinical questions often arise  1. Clinical findings: how to properly gather and interpret findings from the history and examination.  2. Etiology/risk: how to identify causes or risk factors (including iatrogenic harms).  3. Clinical manifestations of disease: knowing how often and when a disease causes its clinical manifestations and classifying patients' illnesses.  4. Differential diagnosis: when considering the possible causes of patient's clinical problems, how to select those that are serious, and responsive to treatment. Central issues in clinical work, where clinical questions often arise  5. Diagnostic tests: how to select and interpret diagnostic tests, to confirm or exclude a diagnosis, based on considering their precision, accuracy, acceptability, safety, expense, and so on.  6. Prognosis: how to estimate our patient's likely clinical course over time and anticipate likely complications of the disorder.  7. Therapy: how to select treatments to offer our patients that do more good than harm and that are worth the efforts and costs of using them.  8. Prevention: how to reduce the chance of disease by identifying and modifying risk factors and how to diagnose disease early by screening. Central issues in clinical work, where clinical questions often arise  9. Experience and meaning: how to empathize with our patients' situations, appreciate the meaning they find in the experience, and understand how this meaning influences their healing.  10. Improvement: how to keep up to date, improve our clinical and other skills, and run a better, more efficient clinical care system. Reports of clinical practice guidelines  It seems that we cannot scan a journal without finding information about a new CPG. CPGs are systematically developed statements to help clinicians and patients with decisions about appropriate health care for specific clinical circumstances.  In addition, they may inform decisions made by policymakers and managers.  Huge amounts of time and money are being invested in their production, application, and dissemination.  The reviews that provide the evidence components for guidelines are “necessity driven” and synthesize the best evidence that can be found to guide an urgent decision that has to be made. Guides for deciding whether a guideline is valid  its developers carry out a comprehensive, reproducible literature review within the past 12 months.  Each of its recommendations both tagged by the level of evidence upon which it is based and linked to a specific citation.  Similar to high-quality clinical decision analysis CDAs and economic analyses, valid practice guidelines should include all relevant strategies (e.g., for diagnosis, screening, prognosis, and/or treatment) and the full range of outcomes (including the good and the bad) that are important. Literature survey database  International literature survey databases include MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials (CENTRAL), LILACS, CINAHL, PsycINFO, Google, and Web of Science. Literature survey databases available in Korea include KoreaMed, KMbase, KISS, and RISS.  A literature survey should be performed with the inclusion of all databases available. However, it may be virtually impossible to search all databases since too much effort and time are required. Therefore, the U.S. NLM provides the scope for a literature survey, which is the COSI (Core, Standard, Ideal) model. Literature survey database  The term "core" means the essence of a literature survey, which is the minimal database required to find the best results rapidly and simply. Therefore, the "core" database is what must be searched.  The group of "core" databases includes MEDLINE, EMBASE, and CENTRAL, while it also includes Korean databases such as KoreaMed, KMbase, KISS, and NDSL.  The term "standard," representing the standard scope of a literature survey, includes a manual search of core journals and the search of databases that are not "core" (Web of Science, DARE, CINAHL, and PsycINFO).  The "ideal" part includes conference proceedings, gray literature, unpublished articles, and clinical trials currently in process. Literature survey database Literature survey strategies  Establish an appropriate survey strategy not only to identify as many pieces of information as possible but also to rapidly detect useful information, and at the same time exclude baseless or inappropriate information.  Survey strategies are classified as strategies to increase sensitivity and strategies to increase specificity.  Sensitivity is defined as the possibility of identifying relevant studies, searching for all the articles relevant to the topic without missing one.  Specificity is defined as the possibility of excluding irrelevant studies, and a strategy to rule out articles that are not relevant to the topic.  A survey with high sensitivity is a comprehensive survey that necessarily includes irrelevant articles.  Literature survey strategies  A strategy to increase sensitivity is aimed at incorporating important studies on a certain topic, and a survey focused on a research topic is one example.  Harmonizing sensitivity and specificity is required in a survey strategy. However, a survey strategy to increase sensitivity is used for literature surveys for research, systematic literature reviews, and the development of clinical practice guidelines, whereas a survey strategy to increase specificity is chosen for literature surveys for knowledge or EBM. Literature survey strategies  In a manual survey, the references cited by the literature retrieved in the database survey may be reviewed, or the Science Citation Index may be used to search relevant literature.  Since an important journal in the current field may not be included in the database to be surveyed, an expert in the field may be consulted. If an important journal is not included in the database, a manual survey should be performed with that journal.  Additionally, surveys may be performed with gray literature, which means literature that has not undergone peer review. Gray literature may include reports and clinical trial registries. Databases that specialize in gray literature include Grey, NTS, and PsycEXTRA.