Using EvidenceBased Practice in Your Practice

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Using Evidence-Based Practice in Your Practice
Richard N. Roberts, Early Intervention Research
Institute 6580 Old Main Hill Utah State
University Logan, UT 84322-6580 www.eiri.usu.edu
Workshop Conducted at the 2005 Summer
Institute in Maternal and Child Health Salt Lake
City, UT July 29, 2005
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Flowchart of Evidence-Based Medicine
Adapted from Jenicek, M. (1997). Epidemiology,
evidence-based medicine, and evidence-based
public health. Journal of Epidemiology, 7,
187-197.
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Selected Examples of Prevention Effectiveness for
Type I Evidence
a Primary prevention is directed at susceptible
persons before they develop a particular disease
(risk factor reduction) secondary prevention is
directed to persons who are asymptomatic but who
have developed biologic changes (early detection
and treatment) tertiary prevention is directed
at preventing disability in persons who have
symptomatic disease (prevention complications and
rehabilitation).
Source Thacker, S. B., Koplan, J. P., Taylor, W.
R., Hinman, A. R. Katz, M. F. Roper, W. L.
(1994). Assessing prevention effectiveness using
data to drive program decisions. Public Health
Reports, 109, 1987-194.
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Considerations for Evaluating the Quality of
Public Health Research Findings
Less Certain Criteria More Certain Criteria One
of a few observations Many observations Anecdote
or case reports Scientific study Not published or
peer-reviewed Published in peer-reviewed
journal Not previously reported Reproduces
findings from other studies Nonhuman
subjects Human subjects Results not related to
hypotheses Results related to tested
hypotheses No limitations mentioned Limitations
mentioned Not compared to previous
results Relationship to previous studies discussed
Source Nelson D. E. (in press). Translating
public health data. In D. E. Nelson, R. C.
Brownson, P. L. Remington, C. Parvanta (Eds.),
Communicating public health information
effectively A guide for public health
practitioners. Washington, DC American Public
Health Association. Riegelman, R. K. (2000).
Studying a study and testing a test (4th
edition). Philadelphia Lippincott.
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Key Characteristics of Evidence-Based Decision
Making

• Intervention Approaches Are Based on the Best
  Possible Science
• Problem Solving is Multidisciplinary
• Theory and Systematic Program Planning Approaches
  are Used
• Second Evaluation Principles are Followed
• Results are Disseminated to Others Who Need to
  Know

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Sequential Framework for Enhancing Evidence-Based
Public Health
Disseminate widely OR Discontinue program or
policy
Refine the issue
Re-tool
Implement
Source Brownson, R. C., Gurney, J. G., Land,
G. (1999). Evidence-based decision making in
public health. Journal of Public Health
Management and Practice, 5, 86-97.
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Criteria for Assessing Causality

• Consistency
• Definition The association is observed in
  studies in different settings and populations,
  using various methods.
• Rule of evidence The likelihood of a causal
  association increases as the proportion of
  studies with similar (positive) results
  increases.
• Strength
• Definition This is defined by the size of the
  relative risk estimate. In some situations,
  meta-analytic techniques are used to provide an
  overall, summary risk estimate.
• Rules of evidence The likelihood of a causal
  association increases as the summary relative
  risk estimate increases. Larger effect estimates
  are generally less likely to be explained by
  unmeasured bias or confounding.

(continued..)
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Criteria for Assessing Causality (continued)

• Temporality
• Definition This is perhaps the most important
  criterion for causalitysome consider it an
  absolute condition. Temporality refers to the
  temporal relationship between the occurrence of
  the risk factor and the occurrence of the disease
  or health condition.
• Rule of evidence The exposure (risk factor)
  must precede the disease.
• Dose-response relationship
• Definition The observed relationship between
  the dose of the exposure and the magnitude of the
  relative risk estimate.
• Rules of evidence An increasing level of
  exposure (in intensity and/or time) increases the
  risk when hypothesized to do so.

(continued..)
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Criteria for Assessing Causality (continued)

• Biological plausibility
• Definition The available knowledge on the
  biological mechanism of action for the studied
  risk factor and disease outcome.
• Rule of evidence There is not a standard rule
  of thumb except that the more likely the agent is
  biologically capable of influencing the disease,
  then the more probable that a causal relationship
  exists.
• Experimental evidence
• Definition The presence of findings from a
  prevention trial in which the factor of interest
  is removed from randomly assigned individuals.
• Rules of evidence A positive result (i.e.,
  reduction in a health condition) after removal of
  the risk factor is strong evidence that the
  factor is causal.

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A Sequential Framework for Understanding the Key
Steps in Developing an Issue Statement
What Why?
What?
How?
Issue Statement Component
Solutions Being Considered
Sample Questions to Consider

• What do the data show?
• What are time trends?
• Are there high-risk populations?
• Can the data be oriented by person, place, and
  time?
• Is public health action warranted?

• What might explain the data being seen?
• Why is the problem being addressed?
• Are there effective (and cost-effective)
  interventions?
• What happens if we do nothing?
• Do we need more information?

• Which options are under active consideration?
• How does ones gain stakeholder input?
• Are resources available for various options?

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Four Key Components of an Issue Statement

• Background/epidemiologic data
• Questions about the program or policy
• Solutions being considered
• Potential outcomes

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Contrasting Approaches to Disease Prevention
Health Area Individual Environmentala Smoking Smo
king cessation classes Cigarette
taxation Hypnosis Clean indoor air
laws Nicotine patch Regulation of cigarette
advertising Stress Stress reduction
classes Reduced work demands Affordable child
care Crime prevention programs Diet/weight
loss Exercise programs Public transportation Cook
ing classes Affordable housing near
workplace How-to-read food labels Urban public
recreation areas Food security programs Food
subsidy programs
Source Adapted from Yen, I. H., Syme, S. L.
(1999). The social environment and health A
discussion of the epidemiologic literature.
Annual Review of Public Health, 20, 287-308. a
Includes the physical, legal, social, and
cultural environments.
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Evidence-Based Practice Matrix
Knowledge Poor
1 Uninformed Professional Judgment (Prior to
1987)
2 Uninformed Prescription (Prior to1999)
National Prescription
Professional Judgment
4 Informed Professional Judgment (In the future)
3 Informed Prescription (After 1999)
Knowledge Rich
Source Adapted from Barber, M. (2002). From good
to great Large-scale reform in England. Paper
presented at Futures of Education conference,
Universitat Zurich, Zurich.