بسم الله الرحمن الرحيم EBM by omayma Saleh

EVIDENCE BASED MEDICINE By Prof Omayma Saleh EBM by omayma Saleh

EVIDENCE BASED MEDICINE History of EBM Al-Razi (Rhazes) Avicenna ( Ibn Sina) EBM by omayma Saleh

Archi Cochrane McMaster University research group led by History of EBM (Cont.): Archi Cochrane McMaster University research group led by David Sackett and Gordon Guyatt EBM by omayma Saleh

Why is EBM important ? EBM by omayma Saleh

Why we must teach EBM? A study in USA suggests that a patient affected with one of a number of common medical disorders is likely to receive appropriate care only half the time. (McGlynn et al,2003) Why?? So , we have to acknowledge that poor clinical decision making reflects, to a considerable degree, shortcoming in the ways doctors are being educated.

And how they remain current as those approaches change?? So, how can doctors be educated so that they are truly current on the optimal approaches for diagnosing and managing the clinical conditions they will encounter in their practice. And how they remain current as those approaches change?? EBM by omayma Saleh

How we have traditionally gained medical knowledge? EBM by omayma Saleh

How we have traditionally gained medical knowledge? 1- Continuing medical education: (evidence: online CME was at least comparable if not superior to traditional CME) 2-Clinical practice guidelines. 3- Expert advice (should complement not replace EBM) 4- Reading . EBM by omayma Saleh

So, what is evidence based medicine? EBM by omayma Saleh

EVIDENCE BASED MEDICINE Evidence-based medicine is the conscientious, explicit and judicious use of current best evidence in making decisions about the care of individual patients. David Sackett In other words Evidence based medicine (EBM) encourages utilization of evidence from clinical research to support clinical decision making for individual patients (Sackett et al. 2000). EBM by omayma Saleh

What is Evidence based health care (EBHC) ? EBHC requires the integration of the best available research evidence with our clinical expertise and our patient’s unique values and circumstances .

EBM by omayma Saleh

Best evidence = best practice EBM by omayma Saleh

Q-An evidence-based approach to practice: A- that you base your practice entirely on randomized controlled trials b B-Discourages decisions which consider patient values and beliefs c C- Provides a framework for incorporating new evidence into your practice d D- is based on strict application of causal thinking. EBM by omayma Saleh

The aim of evidence based clinical practice is: to reduce the wide variations in individual clinician’s practices eliminating worst practices and enhancing best practices thereby reducing costs and improving quality. EBM by omayma Saleh

What are the normal EBM steps towards answering a question What are the normal EBM steps towards answering a question? What is an evidence based approach ? How to practice EBM? EBM by omayma Saleh

STEPS of EBM 5 A ASK : a focused (an answerable) clinical question Acquire : searching for evidence Appraise : critical appraisal of evidence Apply : the evidence based on clinical expertise and patient values. Assess: Evaluate effectiveness and efficacy , keep records and improve the process. EBM by omayma Saleh

What are the most common types of clinical questions? EBM by omayma Saleh

Questions concerning: 1- Clinical evidence: how to gather clinical findings properly and interpret them. 2- Diagnosis: how to select and interpret diagnostic tests. 3- Prognosis: how to anticipate the patient’s likely course? 4-Therapy : how to select treatments that do more good than harm. ( the most common question). 5- Prevention: how to screen and reduce the risk of disease? 6- Education : how to teach yourself, the patient and the family what is needed. EBM by omayma Saleh

Background questions General knowledge about the disorder, test, or treatments Or an overview of a certain area of interest. Usually starts with a root + a verb e.g. What causes a disorder? What , why, when , how? Example: What are the complications of diabetes? What are the causes of generalized oedema? What are the causes of CHF? What are the types of headache? EBM by omayma Saleh

Foreground questions Dealing with a specific knowledge related to patient care decisions and actions. The best search depends on the question type. Example : In a patient with heart failure , does adding an ACE inhibitor improve survival? EBM by omayma Saleh

Step 1: Formulate a focused clinical question ?? PICO: Population / patients = what group due you want information on? Intervention/ exposure/manouver = what medical events do u want to study the effect of ? Comparison = compared to what ? To another intervention or no intervention? Outcome = what is the effect of the intervention? the end point of interest to the patient and doctor, patient oriented not disease oriented. EBM by omayma Saleh

Clinical scenario A 60 years old male patient with no prior history of any cardiovascular event presents to the clinic for follow up . He asks for advice regarding the use of aspirin , as it was recommended for his friend who had a heart attack recently. EBM by omayma Saleh

Formulation of the question: Patients/population: Healthy adults (primary prevention) Intervention : Aspirin Comparison: Placebo Outcome: Prevention cardiovascular morbidity and mortality So, in a healthy adult , does aspirin administration offers protection from cardiovascular diseases ? EBM by omayma Saleh

Clinical scenario A male patient 65 years old , hypertensive (controlled) and has atrial fibrillation of 3 years duration ,has no valvular heart disease or ischemic heart disease. You think if this patient should receive anticoagulant or not. EBM by omayma Saleh

Formulation of the question: Patients/population: Non valvular atrial fibrillation. Intervention : Anticoagulation. Comparison: aspirin Outcome: stroke , haemorrhage. , EBM by omayma Saleh

How to search for evidence? Where? What evidence we search for? EBM by omayma Saleh

Step 2: Searching for best evidence WHERE ??? For broad questions dealing with an overall condition (background questions), the best place is often a textbook. For EBM focused clinical questions , we need to look in the medical literature reported in journals and sometimes clinical guidelines. EBM by omayma Saleh

Sources of evidence are divided to: 1- Primary sources: primary studies reporting original research (non appraised articles) e.g. pubmed/ medline/ clinical queries 2- Secondary sources: those drawing conclusions from original research (appraised articles). EBM by omayma Saleh

Searching for best evidence Electronic search for answers to the formulated question for sources of evidence: Medline Search (Pubmed) : for original articles and systematic reviews. Ready made evidence : very useful but mostly needs subscription: Cochrane library Best evidence ACP journal club Up to date clinical evidence Textbooks are not considered suitable sources of evidence as the information there are usually not up to date ( there are exceptions). EBM by omayma Saleh

Some EBM resources American college of physicians journal club www.acponline.org Clinical evidence: www.clinicalevidence.com www.tripdatabase.com www.infopoems.com (patient oriented evidence that matters) Cochrane library/Cochrane database of systematic reviews Evidence –Based on-call OVID Uptodate www.ahrq.gov/clinic http://www.ICSI.org BMJ updates www.freemedicaljournals.com www.guideline.gov (National Guideline Clearinghouse ) EBM by omayma Saleh

EBM by omayma Saleh

Searching for evidence Select the best answer for the focused clinical question through one or more articles, either: systematic review or original research or guideline Sometimes , no article that exactly addresses the question , so , the closest is selected. EBM by omayma Saleh

Systematic reviews A systematic review is a review of a clearly formulated question that uses systematic methods to identify , select , and critically appraise relevant research and to collect and analyze data from studies that are included in the review. Multiple RCTs are evaluated to answer a specific question. Extensive literature search is conducted (usually by different researchers) to identify studies with sound methodology. The benefit is that multiple RCTs are analyzed not just one study. EBM by omayma Saleh

Meta-analysis This is a systematic review that uses statistical techniques to combine the results of several studies as if they were one large study. EBM by omayma Saleh

Randomized controlled trials (RCTs) Subjects are randomly assigned to a treatment or no treatment or placebo group . RCTs include methods that reduce the potential for bias and that allow for comparison between intervention groups and control groups. Studies are usually double blinded (neither the researcher nor the subject know which intervention they received ) EBM by omayma Saleh

Cohort studies They evaluate (prospective or followed over time) and follow patients who have a specific condition or receive a particular treatment over time and compare them with another group that is similar but has not been affected by the condition being studied, since the two groups may differ in ways other than the variable under study EBM by omayma Saleh

Case control studies Study patients with a specific condition ( retrospective or after the fact ) and compare with people who do not . These are often less reliable than randomized controlled trials and cohort studies because showing a statistical relationship does not mean that one factor necessarily caused by the other. EBM by omayma Saleh

Case reports /case series Consist of collections of reports on the treatment of individual patients without control groups, therefore has much less scientific significance. EBM by omayma Saleh

RCTs > cohort >case control >case series Diagnosis Type of question Suggested type of study Therapy/ Harm RCTs > cohort >case control >case series Diagnosis Controlled Clinical Trial ( prospective blinded comparison to a gold standard) Prognosis Cohort > case control > case series Cost Economic analysis EBM by omayma Saleh

LEVELS OF EVIDENCE The evidence pyramid EBM by omayma Saleh

Levels of evidence (from CEBM) Level 1: RCTs (SR or individual). Level 2: SR of cohort studies or head to head trial. Level 3: Case control studies . Level 4: Case series . Level 5: Expert opinion . EBM by omayma Saleh

How to appraise the evidence ? What is critical appraisal? What does critical appraisal mean? EBM by omayma Saleh

Step 3: Appraise the evidence Validity: good quality studies, well designed. Impact: size of effect or benefit, or does the research suggest a clear and useful plan of action ? Applicability := can the results of the study be applied to my patient OR are the people in the study like my patient? EBM by omayma Saleh

Validity 1- Is the population representative? Or if groups comparable? (Random selection/ Random allocation) 2- Is there adequate follow up ? > 80% 3 - Were the outcome measures unbiased and relevant? ( blinded or objective measures) EBM by omayma Saleh

Impact (size of benefit) The size and significance of the effects. * Statistical significance (CI & P value) * Clinical significance EBM by omayma Saleh

WHAT IS CAT? EBM by omayma Saleh

Critically appraised topic: CAT Critically appraised topic: A short summary of the evidence to a focused clinical question A clinical scenario: a short sentence about the problem A search finding A conclusion: bottom line EBM by omayma Saleh

How to apply the evidence? EBM by omayma Saleh

Step 4: Applying the evidence to individual patients Integrate clinical expertise and patient values and preferences in making clinical decision. What the results mean on average? How the results help in caring for your patient? EBM by omayma Saleh

Step 5: Assess: Evaluate effectiveness , keep a record and improve the process. EBM by omayma Saleh

CLINICAL PRACTICE GUIDELINES A tool for improving quality of health care HOW ??

Guidelines Evidence component : Effects of interventions on a typical patient. Requires validity, importance, up to date. International published levels of evidence. Detailed instruction component: Exact instructions about what to do with patients. Requires local relevance. Usually local site of generation. Grades of recommendation, protocols or flow charts. EBM by omayma Saleh

guidelines produced in one cultural and organizational setting for HOW ? 1- Adapt a CPG: “the use and or modification of guidelines produced in one cultural and organizational setting for application in a different context” .

2- Develop a CPG: If an existing CPG cannot be identified and if sufficient resources and expertise are available.

How to develop recommendations? There are several approaches: GRADE system (The Grading of Recommendation , Assessment and Evaluation system) SIGN system ( The Scottish Intercollegiate Guidelines Network method) SORT system ( Strength Of Recommendation Taxonomy) EBM by omayma Saleh

Is EBM approach to creating guidelines always the right one? The current proliferation and duplication of guidelines is wasteful. Ideally, each speciality group should produce a central repository of evidence that is regularly updated. For each disease, a central evidence base could be built from the available systematic reviews. From this central resource , regional guidelines could be developed , taking account of local resources ,expertise and values and preferences important in that population. Example as a first step : US national guideline clearing house. Fried el al, 2008

Q : In your search for an answer of a clinical question , which one of the following studies you found , would you prefer ? 1- Cohort study 2- Case control study 3- Animal research 4- Systematic review of cohort studies 5- Randomized controlled trial EBM by omayma Saleh

Q Secondary sources of evidence include all of the following except one : 1- Clinical evidence 2- ACP journal club 3- Cochrane systematic reviews 4- Pubmed.com 5- Best evidence EBM by omayma Saleh

A-Textbooks could be a suitable source for evidence. Q-When adopting an EBM approach in clinical practice, one of the following statements is correct: A-Textbooks could be a suitable source for evidence. B-PICO format is a good approach for answering a question. C-We could depend on expert opinion in the absence of suitable source for evidence to answer a specific question. D-When applying the evidence , the doctor should decide whatever the patient’s preferences . E-Critical appraisal should be done whatever the source of the evidence. EBM by omayma Saleh

Thank you EBM by omayma Saleh

Einstein told us the definition of insanity was "doing the same thing over and over again, and expecting different results." EBM by Omayma Saleh