Evidence-based Medicine

Evidence-Based Medicine Dr. Nadira Abbas Al-Baghli

?What is evidence Research Are all research valid and relevant? EBM checks the validity and relevance.

EBM Using current best evidence in decision making in medicine + the expertise of decision makers+ expectations and values of Patients/ people.

Pt e ch. Pain resulting from terminal cancer. She has come to term with her condition. She wishes to receive only palliative treatment. The pt develop pneumoccocal pneumonia. Now evidence that antibiotic therapy reduces mortality from pneumoccocal pneumonia strong.

85- year old man with sever dementia, incontinent, and mute, with out family or friends, who spend his day in apparent discomfort. This man develop pneumococcal pneumonia

A- healthy , 30 years old mother of two children who develop pneumococal pneumonia.

Why we need EBM Our daily need for valid information about Dx, Rx, prognosis, and prevention( up to 5 times per-in pt, and twice for every 3 pts). Expand knowledge Need to be updated Shortage of time for general reading and study. medical textbooks are old and not always based on evidence The disparity betw. Our diagnostic skills and clinical judgment, w increase, and our up-to-date knowledge and clinical performance which decline. CME?

Experienced physicians differ Patho- physiological intuition not work all the time >55 bn $/year spend on research Gap between research and implementation Validity of the research?

Steps for EBM ASK for the required information Acquire (find) the information Appraise the relevance, quality and importance of the information

Apply the information in your practice or Pts.

Formulating questions

Types of questions Background questions: related to anatomy, physiology, biochemistry, pathology, pharmacology Forward questions: interpretation of specific diagnostic test, risk and benefit of a particular treatment or a given Pt prognosis.

Framing the question Dissecting the question into its component parts to facilitate finding the best evidence is a fundamental EBM skills

Determining Q type Therapy: the effect of different therapy Harm: the effect of potentially harmful agents. Diagnosis: establishing the power of an intervention to differentiate between those with or e/o a target condition or disease Prognosis: estimating the future course of a patient’s disease.

P (patients) I (intervention) C ( comparison) O (outcome)

Clinical scenario A 55-year old white women presents with type 2 DM & hypertension. Her glycemic control is excellent on metformin and she has no history of complications. To manage her hypertension, she takes a small daily dose of a thiazide diuretic. Over a 6 mo period, her BP hovers around a value of 155/88 mmHg.

Patients: hypertensive type 2 diabetic pt e/o diabetic complication Intervention: any antihypertensive medication aiming at a target SBP< 140 mmHg Comparison: target systolic BP< 150 mmHg Outcome: stroke, MI, CV death, total mortality

Clinical scenario A father brought in his 2 year old boy because of a “cold” and also concern about his hearing and speech development. He thought the boy sometimes heard well and other days appeared deaf. Clinical Ex showed dull tympanic membranes with retraction on the left. I wondered how accurate the clinic’s microtympanometer was for the Dx of OM with effusion and Eustachian tube dysfunction & formulated the Question.

what is the accuracy of microtympanometry for the diagnosis of hearing loss from a middle ear effusion in young children?

Search the evidence (tympanomet* OR impedance) AND (otitis media OR middle ear) AND audiomet* (MEDLINE)

Abdul-Rahman, is a moderately obese 56 years-old man with type 2 DM, smokers, with no DM complication, his blood sugar are well controlled on metformin but his BP has been mildly elevated, he is not keen to consume additional medication, and like to see the evidence that lowering BP with drugs does more good than harm for people in his case

In a 56- year old man with type 2 DM and untreated hpt, does tight BP control reduce subsequent morbidity and mortality.

Hessa is a 71 years old widow with no important health problem until she awake one morning with Rt arm clumsiness. Ex. BP 154/84, you detect Lt carotid bruit, CV and neurological ex was normal. Your Dx transient ischemic attack (TIA) and you prescribe aspirin, you have recently heard about the benefit of carotid endarterctomy, for high grade carotid stenosis, and you would order quick and safe carotid US, but colleague told you of a similar pt who had a positive carotid US but negative angiogram, and wondering how good US in detecting treatable carotid lesion

In a 71 year-old women with a recent TIA, is carotid US a trustworthy intermediate step to angiography in diagnosing surgically remediable carotid stenosis?

Nouf, a 46 years old women, has ulcerative colitis ( UC), with extensive involvement of colon. She is loath to have surgery but concern about the risk of cancer, and like to find out what the risk might be.

In a 46 year old women with extensive UC, what is the risk for developing bowel cancer?

“Ulcerative colitis” AND neoplasm AND cohort studies

A 29 years old man presents with recurrent furunculosis for past 10 months; the episodes have been treated with drainage & several courses of antibiotics but keep recurring. He ask if recurrence can be prevented.

P: patients with recurrent furunculosis I: prophylactic antibiotics C: no treatment O: reduction in recurrence of furunculosis