Evidence-Based Medicine: What does it really mean? Sports Medicine Rounds November 7, 2007

What is Evidence-Based Medicine? A Philosophical Framework? An Evolving Concept? A Method of Practice? A Quality Improvement Approach? A Teaching Tool? A Potentially Dangerous Thing if used Incorrectly? ALL OF THE ABOVE

A New Concept? The concept of modifying clinical practice based on research results has been in place for hundreds, perhaps thousands of years In the 20 th century (1990’s+) it has evolved to impact almost all fields of healthcare and policy; a structured approach

Largely Developed by One Group The specific methodologies used to determine “best evidence” were largely established by a research group led by David Sackett & Gordon Guyatt at McMaster U.

“Evidence-based medicine is the conscientious, explicit, & judicious use of current best evidence in making decisions about the care of individual patients” David Sackett, 1996 What is Evidence-Based Medicine?

“The integration of best research evidence with clinical expertise & patient values” Sackett et al, 2000 What is Evidence-Based Medicine?

Types of Evidence-Based Medicine Evidence-based guidelines (EBG): practice of EBM at the organizational, institutional, or group level (establishing guidelines, policy, regulations)

Types of Evidence-Based Medicine Evidence-based individual decision making (EBID): EBM as practiced by the individual healthcare provider in determining how to treat patients Some are suggesting we may be too EBM focused

Evidence-Based Medicine: A Process 1. Identify a patient-oriented/practice- oriented problem that is of interest 2. Develop a specific clinical question that targets the problem 3. Review the available evidence 4. Appraise the evidence → Decision 5. Integrate the evidence into your practice 6. Assess your outcomes (if appropriate)

Important not to confuse Levels of Evidence with Quality of Evidence or Importance An Idealistic EBM Model

Study Design Should Match “?” RCT: Homogeneous patients randomized to intervention A or B & compare outcomes Longitudinal Cohort: Compare a group of people with a risk factor over time to see who develops a disease/injury; prognosis

Study Design Should Match “?” Case-Control: People with condition are compared to those without on a set of variables to assess effect(s) or associations with variables; Diagnostic or descriptive Cross-sectional Survey: A sample from a population is assessed for a certain disease/finding and specific risk factors at that single point in time; descriptive

Systematic Reviews & Meta-analyses Systematic Review: Structured review of the literature Set inclusion & exclusion criteria Assess study design quality Assess methodological quality (rarely) Compile & summarize results Goal: determine what the current evidence is on a specific topic

Systematic Reviews & Meta-analyses Meta-Analysis: Also a structured review of the literature Set inclusion & exclusion criteria Assess study design quality Assess methodological quality (rarely) Perform statistics on the integrated results of the grouped studies Goal: draw conclusions from the results of the analysis of the grouped data

Systematic Reviews Goal: Summaries of best evidence; information overload Top level of evidence; everyone doing them Most are fair in terms of value Over 1.3 Million listed in MEDLINE alone About 5000 on the knee alone Need to evaluate carefully

Systematic Review Killers Low level research / Lack of Research Heterogeneity of subject pools Heterogeneity of methodology Lack of detail prohibits comparison Authors are often knowledgeable on general topic & evaluating study design & sources of bias, but not intervention methods

Must be Savvy Consumers of the Scientific Literature Cannot just read abstract, conclusions, & look at figures Hypotheses, methods, & results are most important Design appropriate? Bias? Conclusion based on results & consistent with methods?

Things to Consider EBM is only as good as the data available A quality case-control study is more meaningful than a flawed RCT Thus, systematic reviews of RCTs are not necessarily best evidence

Final Thoughts Payers have also adopted this Lack of evidence is being equated with lack of benefit; this is not true (call for evidence) There are other clinical decision-making approaches There are highly reputed health care experts who are stark opponents to the EBM approach accepted by most

Patient-Based Outcomes Measures What do they tell us? Does the KOOS QOL tell us someone’s knee is healthy? Can it tell us how well someone is doing or does it simply tell us if there is noteworthy disability or not? Is the difference between an 80 & 88 on the score the same as 88 to 96? What is a good score? In a young athlete?