ebph handout
TRANSCRIPT
“…If we did not respect the evidence, we would have very little leverage in our quest for the truth.”
Carl Sagan
Getting the Evidence:An introduction to Evidence-Based Public Health
Fall 2007
Erika L. Sevetson, MS
Ebling Library, UW – Madison
Session Objectives
Learn the definition of EBPH Introduction to the process of EBPH Learn steps to finding the evidence
Definition: Evidence-based Public Health “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.
Community Needs & Values
Scientific Evidence
Resources
(adapted and modified from Muir Gray)
EBPH
Key Differences between EBM and EBPHCharacteristic Evidence-Based Medicine Evidence-Based Public
Health
Quality of evidence Experimental studies Observational and quasi-experimental studies
Volume of evidence Larger Smaller
Time from intervention to outcome
Shorter Longer
Professional training of workforce
More formal, with certification and /or licensing
Less formal, no standard certification
Decision making Individual Team
Why is EBPH important?
Provides assurance that decision making is based on scientific evidence and effective practices
Helps ensure the retrieval of up-to-date and reliable information about what works and doesn’t work for a particular public health question
Provides assurance that one’s time is being used most efficiently and productively in reviewing the “best of the best” information available on the particular public health question
Why is EBPH important?
During the past century, average life expectancy increased by approximately 30 years in industrialized countries
Only about 5 years of that improvement is attributable to preventive services and medical care
- Bunker et. al. 1994
Some Key Characteristics of EBPH Intervention approaches developed based on
the best possible scientific information Theory and systematic planning approaches
are followed Problem solving is multi-disciplinary Sound evaluation principles are followed Results are disseminated to others who need
to know and take action
Advantages to Using EBPH
Higher likelihood of success― A move away from decision-making that relies too
heavily on:• History• Anecdotes• Pressure from policy makers
Identify common indicators Defend/expand an existing program Advocate for new programs New knowledge is generated to help others
When is EBPH used?
when it’s important to have scientific evidence to support decision making
when evaluating the effectiveness and cost benefits of health programs
when establishing new health programs when policies are being implemented when conducting literature reviews for grant
projects.
Steps in the EBPH Process
1) Formulating a clear question from a public health problem2) Searching the literature3) Appraising the evidence4) Selecting the best evidence for a public health decision5) Linking evidence with public health experience,
knowledge, practice, and the community’s values and preferences
6) Implementing findings in public health practice and programs
7) Evaluating results.
Source: Jenicek, Milos and Sylvie Stachenko. 2003. Evidence-based public health, community medicine, preventive care. Medical Science Monitor: 9(2): p, SR2.
Evidence-Based Public Health
Define the issue
Quantify the issue Conduct literature
review
Develop program or policy options
Develop planEvaluate the
program or policy
Steps in Searching the Public Health Literature
Source: Adapted from Brownson. Evidence-based public health. Oxford University Press, 2003, p. 128.
1. Determine the public health problem and define the question
2. Select information sources 3. Identify key concept and terms4. Conduct the search5. Select documents for review6. Abstract relevant information from the
documentation7. Summarize and apply the literature review
Step 1: Determine/Define the question (Evidence types)
Type 1 Something should be done
Type 2 This should be done
Type 3 How 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
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
Types & Sources 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.
Source: R.C. Brownson et al, Evidence-Based Public Health, Oxford: Oxford University, 2003.
Types & Sources of Evidence
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.
Source: Guide to Research Methods: The Evidence Pyramid: <http://servers.medlib.hscbklyn.edu/ebm/2100.htm>.
Types & Sources of Evidence
Journal literature:
“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….
Types & Sources of Evidence
Best Practices: Public health programs, interventions, and policies that through experience have been evaluated, shown to be successful, and have the potential to be adapted and transformed by others working in the same field.
— Lacks rigorous evaluation of a systematic review or meta-analysis
— Applied across a variety of public health areas— Vary widely in scope, methods, and quality
— Expert opinion to systematic methods— Some are very influential
— Best Practices for Comprehensive Tobacco Control Programs
Evidence spectrum
Meta analysis/ Systematic Meta analysis/ Systematic review/ Evidence-based review/ Evidence-based guidelinesguidelines
Weak StrongStrong
No evidence/ case reports
Best PracticesLocal needs assessment
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
Iexercisephysical activityrecreation
program developmentprogram evaluationeffective programs
Step 4: Searching the literature
Best Evidence Resources
http://ebling.library.wisc.edu/EBPH
Cochrane Collaboration
PubMed
Partners in Information Access for the Public Health Workforce
NICHSR: National Information Center on Health Services Research & Health Care Technology
Step 7: Summarize and apply the literature review Appraising the Evidence & Evaluating the Results
―What type of study/evidence is it?―What are the results?―Are the results valid?―Were all important outcomes considered?―Was an explicit process used to ID evidence?―Has the guideline been subjected to peer review
and testing?―Can the results be applied to my context?
