Evidence based medicine

This topic is very essential for Pharm.D students. It includes application, benefits, limitations of EBM. It also includes EBM history and background which helps you for examinations. EBM is very important topic in Pharmacotherapeutics-III so you may find this needful.
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1. Sri Ramya Vaddiparthy Evidence Based Medicine

2. Definition . Evidence based medicine  ( EBM ) is the conscientious, explicit, judicious and reasonable use of modern, best evidence in making decisions about the care of individual patients.  EBM  integrates clinical experience and patient values with the best available research information.  The term was originally used to describe an approach to teaching the practice of medicine and improving decisions by individual physicians about individual patients.

3. Background & History Medicine has a long history of scientific inquiry about the prevention, diagnosis, and treatment of human disease . The concept of a controlled clinical trial was first described in 1662 by  Jan Baptist van Helmont  in reference to the practice of bloodletting-Wrote Van Helmont . The first published report describing the conduct and results of a controlled clinical trial was by  James Lind , a Scot Naval Surgeon who conducted research on scurvy during his time aboard HMS Salisbury in the Channel Fleet, while patrolling the Bay of Biscay.

4. Lind divided the sailors participating in his experiment into six groups, so that the effects of various treatments could be fairly compared. Lind found improvement in symptoms and signs of scurvy among the group of men treated with lemons or oranges. He published a treatise describing the results of this experiment in 1753. An early critique of statistical methods in medicine was published in 1835. The term "Evidence-based medicine" was introduced in 1990 by  Gordon Guyatt  of  McMaster University

5. EBM Triad

6. Source

7. 5A’s of EBM

8. Principles of EBM The practice of EBM involves five essential steps- 1)Converting information needs into answerable questions, 2) Finding the best evidence with which to answer the questions 3) Critically appraising the evidence for its validity and usefulness 4)Applying the results of the appraisal into clinical practice 5)Evaluating performance.

9. Step 1 One of the difficult steps in practising EBM may be the translation of a clinical problem into an answerable question. When we come across a patient with a particular problem, various questions may arise for which we would like answers. These questions are frequently unstructured and complex, and may not be clear in our minds. The practice of EBM should begin with a well formulated clinical question. This means that we should develop the skill to convert our information needs into answerable questions. Good clinical questions should be clear, directly focused on the problem at hand, and answerable by searching the medical literature.

10. A good clinical question should have four (or sometimes three) essential components: The patient or problem in question The intervention, test, or exposure of interest; Comparison interventions (if relevant) T he outcome, or outcomes of interest.

11. PICO Thus an answerable clinical question should be structured in the PICO (Patient or Problem, Intervention, Comparison, Outcome/s) or PIO (Patient or Problem, Intervention, Outcome/s) format

12. Step 2 Once you have formulated your clinical question, the next step is to seek relevant evidence that will help you answer the question. There are several sources of information that may be of help. Traditional sources of information such as textbooks and journals are often too disorganised or out of date.8 You may resort to asking colleagues or ‘‘experts’’ but the quality of information obtained from this source is variable. Secondary sources of reliable summarised evidence which may help provide quick evidence based answers to specific clinical questions include Archimedes , Clinical Evidence and BestBets .Other important sources of evidence include the online electronic bibliographic databases, which allow thousands of articles to be searched in a relatively short period of time

13. Step 3 After you have obtained relevant articles on a subject, the next step is to appraise the evidence for its validity and clinical usefulness. Although there is a wealth of research articles available, the quality of these is variable. Research evidence may be appraised with regard to three main areas: validity, importance, and applicability to the patient or patients of interest. Critical appraisal provides a structured but simple method for assessing research evidence in all three areas

14. Step 4 When we decide after critical appraisal that a piece of evidence is valid and important, we then have to decide whether that evidence can be applied to our individual patient or population. In deciding this we have to take into account the patient’s own personal values and circumstances. The evidence regarding both efficacy and risks should be fully discussed with the patient or parents, or both, in order to allow them to make an informed decision

15. Step 5 As we incorporate EBM into routine clinical practice, we need to evaluate our approach at frequent intervals and to decide whether we need to improve on any of the four steps. We need to ask whether we are formulating answerable questions, finding good evidence quickly, effectively appraising the evidence, and integrating clinical expertise and patient’s values with the evidence in a way that leads to a rational, acceptable management strategy. Formal auditing of performance may be needed to show whether the EBM approach is improving patient care.

16. Benefits One of the significant  benefits  of  EBM  is that using of the evidence based practice allows the clinician to adapt treatment to the conditions and risk– benefit  profile of the individual patient, which in turn, leads to better health outcomes.

17. Misconceptions Misconception Clarification EBM is “cookbook” medicine: overly dogmatic, inflexible, too uniform (one-size-fits-all). EBM can be based on any reasonable evidence. High-quality evidence based on basic science and surrogate outcomes can reliably be used to determine best practices for patient care. EBM is inherently meant to tailor best evidence to the needs and preferences of a particular patient, based on the clinical judgement of a conscientious and capable clinician. EBM is based on  best-available evidence , which requires evaluation of all relevant evidence and grading its quality. Ideally, EBM uses  patient-oriented evidence  (i.e., outcomes of importance to patients, such as morbidity, mortality, and quality of life) rather than  disease-oriented evidence  (e.g., physiologic variables, blood test results) when making clinical decisions

18. Many clinicians mistakenly believe that applying some evidence is practicing EBM. That depends, however. What counts is basing clinical decisions on the best available evidence, not just any evidence. It also does not mean that we are paralyzed when good evidence to guide us is not available. We have all had the experience of seeing one randomized clinical trial contradicted by another. This is especially true when trials measure surrogate outcomes such as blood pressure or blood glucose level rather than patient-oriented outcomes, when study populations and interventions differ in important ways, or when trials have different levels of intentional or unintentional bias.

19. Applications of evidence in Clinical Setting. Despite the emphasis on evidence-based medicine, unsafe or ineffective medical practices continue to be applied, because of patient demand for tests or treatments, because of failure to access information about the evidence, or because of the rapid pace of change in the scientific evidence. For example, between 2003 and 2017, the evidence shifted on hundreds of medical practices, ranging from whether hormone replacement therapy was safe to whether babies should be given certain vitamins to whether antidepressant drugs are effective in people with Alzheimer's disease. Even when the evidence is unequivocally against a treatment, it usually takes ten years for other treatments to be adopted. In other cases, significant change can require a generation of physicians to  retire or die, and be replaced by physicians who were trained with more recent evidence .

20. Physicians may also reject evidence which conflicts with their anecdotal experience or because of cognitive biases – for example, a vivid memory of a rare but shocking outcome (the availability heuristic), such as a patient dying after refusing treatment .  They may overtreat to "do something" or to address a patient's emotional needs. They may worry about malpractice charges based on a discrepancy between what the patient expects and what the evidence recommends.  They may also over treat or provide ineffective treatments because the treatment feels biologically plausible .

21. Limitations Although evidence-based medicine is regarded as the gold standard of clinical practice, there are a number of limitations and criticisms of its use . Research can be influenced by biases such as publication bias and conflict of interest in academic publishing . For example, studies with conflicts due to industry funding are more likely to favor their product . There is a lag between when the RCT is conducted and when its results are published . There is a lag between when results are published and when these are properly applied . Hypocognition (the absence of a simple, consolidated mental framework that new information can be placed into) can hinder the application of EBM . Values: while patient values are considered in the original definition of EBM, the importance of values is not commonly emphasized in EBM training, a potential problem under current study

22. References https://en.wikipedia.org/wiki/Evidence-based_medicine https://adc.bmj.com/content/archdischild/90/8/837.full.pdf https://www.aafp.org/afp/2018/0915/p343.html