Evidence-Based Public Health

Objectives and Competencies Learn the definition of EBPH Introduction to the process of EBPH Describe steps associated with EBPH in public health. Identifies relevant and appropriate data and information sources.

Definitions Evidence Public Health Evidence-based Medicine Evidence-based Public Health

“…If we did not respect the evidence, we would have very little leverage in our quest for the truth.” Carl Sagan

Evidence The available body of facts or information indicating whether a belief or proposition is true or valid”.

Evidence-based Medicine apply the best available evidence gained from the scientific method to clinical decision making assess the strength of evidence of treatments and diagnostic tests. Evidence quality can range from meta analyses and systematic reviews of double blind, placebo-controlled clinical trials at the top end, down to conventional wisdom at the bottom.

Emerge of Evidence-Based Medicine  First described in 1992  A new approach to teaching medicine  A “revolution” in medical practice  Other “evidence-based” approaches: ethics, psychotherapy, occupational therapy, dentistry, nursing, and librarianship

Driving Factors of EBM  Overwhelming size of the literature  Inadequacy of textbooks  Difficulty synthesizing evidence and translating into practice  Increased number of RCTs  Available computerized databases  Reproducible evidence strategies

Definition of EBM “The integration of best research evidence with clinical expertise and patient values.”

Steps of EBM ► Convert the need for info. into an answerable question ► Track down the best evidence ► Critically appraise that evidence ► Integrate the appraisal with one’s clinical expertise and the individual patient ► Evaluate Sackett DL. EBM: how to practice and teach EBM. Churchill Livingstone 2000

Critique of EBM De-emphasizes patient values Doesn’t account for individual variation Devalues clinical judgment Leads to therapeutic nihilism

Evidence-based Public Health  Definition: “the development, implementation, and evaluation of effective programs and policies in public health through application of principles of scientific reasoning, including systematic uses of data and information systems, and appropriate use of behavioral science theory and program planning models” Source: Brownson, R.C. et al, Evidence-based public health, Oxford University Press, 2003.

Development of EBPH Jenicek (1997) published a review discussing epidemiology, EBM, EBPH Epidemiology described as the foundation of both EBM and EBPH EBPH unique in using complex interventions with multiple community and societal issues

Evidence-based Public Health is the leading edge of modern public health practice

Steps of EBPH ► Develop an initial statement of the issue ► Search the scientific literature and organize information ► Quantify the issue using sources of existing data ► Develop and prioritize program options; implement interventions ► Evaluate the program or policy

Community Needs & Values Scientific Evidence Resources (adapted and modified from Muir Gray) EBPH

EBM and EBPH Parallels State the scientific question of interest Identify the relevant evidence Determine what information is needed to answer the scientific question Determine the best course of action considering the patient or population Evaluate process and outcome

Differences between EBM and EBPH CharacteristicEvidence-Based MedicineEvidence-Based Public Health Quality of evidenceExperimental studiesObservational and quasi- experimental studies Volume of evidenceLargerSmaller Time from intervention to outcome ShorterLonger Professional training of workforce More formal, with certification and /or licensing Less formal, no standard certification Decision makingIndividualTeam

Steps in the EBPH Process 1. Define a public health problem; 2. Identify information to solve problems; 3. Searching the literature; 4. Critical appraisal of the evidence; 5. Selecting the best evidence for a public health decision; 6. Linking evidence with public health experience, knowledge, practice, and the community’s values and preferences; 7. Implementing findings in public health practice and programs (intervention); 8. Evaluating results. Source: Jenicek, Milos and Sylvie Stachenko Evidence-based public health, community medicine, preventive care. Medical Science Monitor: 9(2): p, SR2.

Evidence-Based Public Health Define the issue Quantify the issueConduct literature review Develop program or policy options Develop plan Evaluate the program or policy

Steps in Searching the Public Health Literature 1. Determine the public health problem and define the question 2.Select information sources 3.Identify key concept and terms 4.Conduct the search 5.Select documents for review 6.Abstract relevant information from the documentation 7.Summarize and apply the literature review Source: Adapted from Brownson. Evidence-based public health. Oxford University Press, 2003, p. 128.

Appraising the Evidence & Evaluating the Results  What are the results?  Are the results valid?  How can the results be applied to public health practice and interventions?

Source: Guide to Research Methods: The Evidence Pyramid:.

Hierarchy of Research Designs Category I: Evidence from at least one properly randomized controlled trial. Category II-1: Evidence from well-designed controlled trials without randomization. Category II-2: Evidence from well-designed cohort or case-control analytic studies, preferably from more than one center or research group.

Category II-3: Evidence from multiple times series with or without intervention or dramatic results in uncontrolled experiments such as the results of the introduction of penicillin treatment in the 1940s. Category III: Opinions of respected authorities, based on clinical experience, descriptive studies and case reports, or reports of expert committees. Source: Harris, R.P. et al. (2001). Current methods of the U.S. Preventive Services Task Force: a review of the process. American Journal of Preventive Medicine. April 20 (3 Supplement): 21-35

Types of Evidence Systematic Review: critical assessment and evaluation of research that attempts to address a focused question using methods designed to reduce the likelihood of bias. Meta-Analysis: overview that incorporates a quantitative strategy for combining the results of several studies into a single pooled or summary estimate. Risk Assessment: systematic approach to characterizing the risks posed to individuals and populations by environmental pollutants and other potentially adverse exposures.

Decision Analysis: systematic approach to decision making under conditions of uncertainty; involves identifying all available alternatives and estimating the probabilities of potential outcomes associated with each alternative, valuing each outcome, and, on the basis of the probabilities and values, arriving at a quantitative estimate of the relative merit of the alternatives. Economic Evaluation: comparative analysis of alternative courses of action in terms of both their costs and consequences. Expert Panels: examination of research studies and their relevance to health conditions, diagnostic and therapeutic procedures, planning and health policy, and community interventions.

Practice Guidelines: systematically developed statements to assist practitioner and patient decisions about appropriate health care for specific clinical circumstances; may be developed by government agencies, institutions, or by the convening of expert panels. Source: R.C. Brownson et al, Evidence-Based Public Health, Oxford: Oxford University, 2003.

Evidence spectrum Meta analysis/ Systematic review/ Evidence-based guidelines WeakStrong No evidence/ case reports Best Practices Local needs assessment

“The best is the enemy of the good” -Voltaire

The effectiveness of parachutes has not been subjected to rigorous evaluation by using randomised controlled trials…. We think that everyone might benefit if the most radical protagonists of evidence based medicine organised and participated in a double blind, randomised, placebo controlled, crossover trial of the parachute. Smith and Pell, BMJ, 2004 The problem of randomized trials and parachutes….

PubMed Cochrane Collaboration TRIP Database NICHSR: National Information Center on Health Services Research & Health Care Technology Partners in Information Access for the Public Health Workforce Lamar Soutter Library: EBPH Project Best Evidence Resources

Step 1: Determine/Define the question (Evidence types) Type 1Something should be done Type 2This should be done Type 3How the intervention should be done

Step 1: Determine/Define the question P =Patient/Population/Problem I =Intervention/Item of interest C =Comparison O =Outcome

You coordinate social activities for a few of the city’s senior centers. The latest Behavioral Risk Factor Surveillance System (BRFSS) survey showed that seniors in your state are not participating in regular exercise or many other health promotion behaviors. You’ve heard that physical activities for older adults can have a host of benefits, and would like to submit a grant to begin an exercise program. You must find literature supporting the effect of exercise programs in reducing injuries or decreasing risk of chronic disease in the elderly. A Scenario P I O C – no comparison/placebo I

 P = inactive seniors  I = community exercise programs  C = no comparison  O = reduced injuries/chronic disease PICO

The question…  In inactive senior populations, are formal exercise programs effective in reducing injuries and chronic disease associated with the aging process?

Step 2: Select information sources  Systematic Reviews and Meta-analyses  Practice Guidelines  Journal Literature  Best Practices

Step 3: Identify key concept and terms  In inactive senior populations, are formal exercise programs effective in reducing injuries and chronic disease associated with the aging process?

 P = inactive seniors  I = community exercise programs  C = no comparison  O = reduced injuries/chronic disease Step 3: Identify key concepts and terms P Seniors/senior citizens elderly aged I exercise physical activity recreation program development program evaluation effective programs

Step 4: Searching the literature  Best Evidence Resources