An%20Introduction%20to%20Evidence-Based%20Public%20Health

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An Introduction to Evidence-Based Public Health

• Neal D. Kohatsu, MD, MPH
• Associate Professor
• Dept. of Epidemiology

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Case Presentation
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Case Presentation

• Assume that you are the health director of a
  local health department.
• A community in your jurisdiction is concerned
  with its high rate of childhood obesity and
  requests your help.
• How do you proceed?

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Overview

• Rise of evidence-based medicine
• Development of evidence-based PH
• Current perspective on PH
• New definition of EBPH
• Evaluating and improving EBPH
• Review of case presentation
• Summary

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Rise of Evidence-Based Medicine
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Rise 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

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Factors Driving EBM
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Factors Driving 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

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Definition of EBM

• The integration of best research evidence with
  clinical expertise and patient values.

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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 ones clinical
  expertise and the individual patient
• Evaluate

Sackett DL. EBM how to practice and teach EBM.
Churchill Livingstone 2000
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Critique of EBM

• De-emphasizes patient values
• Doesnt account for individual variation
• Devalues clinical judgment
• Leads to therapeutic nihilism

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Parachute use to prevent death and major trauma
related to gravitational challenge systematic
review of randomised controlled trials. Smith
GC, Pell JP. BMJ 3271459-1461 2003.
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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

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Definition of EBPH (1)

• EBPH is the conscientious, explicit, and
  judicious use of current best evidence in making
  decisions about the care of communities and
  populations in the domain of health protection,
  disease prevention, health maintenance and
  improvement.
• Jenicek (1997)

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Definition of EBPH (2)

• EBPH is 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 program planning models.
• Brownson (1999)

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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

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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 ones clinical
  expertise and the individual patient
• Evaluate

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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

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Cochrane Collaboration

• Mission
• an international organisation that aims to help
  people make well-informed decisions about health
  care by preparing, maintaining and promoting the
  accessibility of systematic reviews of the
  effects of healthcare interventions.

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Structure of the Collaboration

• Collaborative Review Groups
• Methods Groups
• Fields
• Consumer Network
• Centres

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Guide to Community Preventive Services

• Developed by the U.S. Task Force on Community
  Preventive Services
• Supported by the U.S. Centers for Disease Control
  and Prevention (CDC)
• Based on systematic reviews
• Recommendations based on strength of evidence

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Topic Areas

• Vaccine-preventable diseases
• Tobacco use prevention and control
• Reducing motor vehicle occupant injury
• Diabetes

• Physical activity
• Oral health
• Social Environment
• Prevention of injuries due to violence
• Cancer

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A Current Perspective on PH

• Public health encompasses
• the efforts, science, art, and approaches used
  by all sectors of society to assure, maintain,
  protect, promote, and improve the health of the
  people.

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Public Health

• Communities
• Healthcare system
• Employers business
• Media
• Academia
• Government

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Definition of EBPH (3)

• The process of integrating science-based
  interventions with community preferences to
  improve the health of populations.

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The Future of Evidence-Based Public Health

• How can we evaluate and improve EBPH in practice?

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Improving EBPH in Practice

• Quality of the Science Base
• Community Involvement
• Effect on Public Health Outcomes

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Improving the Qualityof the Science Base

• Moving beyond RCTs
• Transparent Reporting of Evaluations with
  Non-randomized Designs (TREND)
• Grading of Recommendations Assessment,
  Development and Evaluation (GRADE)

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Improving Community Involvement
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Improving Community Involvement

• Public health institutions should provide
  communities with the information they have that
  is needed for decisions on policies or programs
  and should obtain the communitys consent for
  their implementation.
• --Public Health Leadership Society

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Informed Consent at the Community Level

• Community-based participatory research
• Community advisory boards

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Improving EBPH Outcomes

• Difficult to assess
• Issues of sample size, contamination, blinding,
  long-term follow-up
• Ethical constraints of withholding evidence
• Patients do better in the real world when
  provided with evidence-based therapy

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Case Presentation

• Assume that you are the health director of a
  local health department.
• A community in your jurisdiction is concerned
  with its high rate of childhood obesity and
  requests your help.
• How do you proceed?

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Develop an InitialStatement of the Issue

• The prevalence of obesity among the 327
  elementary school children in the community is
  35. With the support of parents, school staff,
  and community-based organizations, how can this
  obesity rate be reduced through lifestyle
  interventions?

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Quantify the Issue

• The prevalence of obesity was determined by a
  special survey.
• The rate of obesity was found to increase by
  grade level.
• The rates were about equal in girls and boys.
• 100 minutes/wk provided at school for physical
  activity, but only 40 minutes is guided by a
  teacher.

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Search the Scientific Literature and Organize
Information

• Medline search
• Cochrane Collaboration
• Task Force on Community Preventive Services

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Task Force on Community Preventive Services

• Insufficient evidence to recommend
  classroom-based health education to provide
  information on managing health risks.
• Strongly recommended curricula and policies to
  increase the amount of moderate or vigorous
  activity, increase the amount of time in PE
  class, or the amount of time being active in PE.

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Develop and PrioritizeProgram Options

• A community-based work group develops a number of
  options to increase physical activity in school.
• There are debates about losing time in the
  classroom and impact on test performance.

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Develop an Action Plan
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Develop an Action Plan

• Agreement is reached on a pilot project for the
  next school year involving reducing the lunch
  hour and increasing time in physical education
  with an emphasis on activities that get all
  children to be active.
• The program will be evaluated by all stakeholders
  (e.g., children will be surveyed)

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Summary

• EBM has transformed medicine
• EBM has fostered development of EBPH
• EBPH continues to evolve
• Increased community engagement