Dr. Yasser Ahmed Abdelrahman Lecturer of anesthesia and intensive care Ain shams university, Faculty of Medicine June, 2012. EVIDENCE BASED MEDICINE. HYPETHESIS. Hypo-ti-thenai To put under or Suppose. HYPETHESIS. observation. understanding. intuition. HYPOTHESIS TESTING.
Dr. Yasser Ahmed Abdelrahman
Lecturer of anesthesia and intensive care
Ain shams university, Faculty of MedicineJune, 2012
Hypo-ti-thenaiTo put under or Suppose
“To get the right answer,
you must first ask the right question.”
Experience with Condition
What modes of ventilation can cause barotrauma?
Background questions are typically answered by textbooks.
Is APRV protective against barotrauma in patients with ARDS?
Foreground questions are typically answered by databases that access the research literature
“Background” question composed of question modifier and condition.
Cover the full range of biologic, psychologic, or sociologic aspect of human illness
Can be answered by reference works.*
Can be used as a trampoline for generating specific questions to be answered by EBM.
“Foreground” question composed of patient and/or problem, intervention (therapy, diagnostic test, etc.), comparison and outcome.
Often requires more comprehensive and intensive search strategies (not necessarily more time consuming).
Suitable to answering using the techniques of EBM.
Formulate three part question
Types of Questions
Question Templates for Asking PICO QuestionsTherapyIn __________________, what is the effect of ____________________ on ______________________ compared with __________________?EtiologyAre ______________ who have _________________ at ________________ risk for/of ____________________ compared with _____________________ with/without ______________________?Diagnosis or Diagnostic TestAre (Is) _________________________ more accurate in diagnosing ________________ compared with ________________?PreventionFor _________________ does the use of _______________ reduce the future risk of ________________ compared with _________________?PrognosisDoes _______________ influence _________________ in patients who have __________________?
Melnyk, B. M., & Fineout-Overholt, E. (2005). Evidence-based practice in nursing & healthcare : A guide to best practice. Philadelphia, PA: Lippincott Williams & Wilkins.
Randomized Controlled Trial
Case Control Studies
Case Series/Case Reports
obtained from at least one properly controlled randomized trial, considered the gold standard of evidence.
derived from controlled trials without randomization.
well-designed cohort or case-control studies.
includes studies with external control groups or ecological studies.
evidence is derived from reports of expert committees, not because it is weaker than levels I or II, but because it is often difficult to ascertain the scientific origin of the committee opinion.
Introduction: why the authors decided to conduct the research.
Methods: how they conducted the research and analyzed their results.
Results: what was found.And
Discussion: what the authors think the results mean.
Flaherty, Robert J. A simple method for evaluating the clinical literature. Fam Prac Mgt, May 2004;47-52. Available online at http://www.aafp.org/fpm/20040500/47asim.html.
STUDY DESIGN APPROPRIATE TO OBJECTIVES
STUDY SAMPLE REPRESENTATIVE
CONTROL GROUP ACCEPTABLE
QUALITY OF MEASUREMENTS AND OUTCOMES
IS EVIDENCE BASEDMEDICINE DEAD?Trisha GreenhalghProfessor of Primary CareUniversity College London