Finding, Evaluating, and Presenting Evidence

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Finding, Evaluating, and Presenting Evidence

• Sharon E. Lock, PhD, ARNP
• NUR 603
• Spring, 2001

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Sources of Knowledge

• Intuition
• Trial and error
• Tradition
• Authority
• Experience
• Scientific

3
Sources of knowledge

• not all sources of knowledge are highly
  reliable, nor when applied do they consistently
  produce desired outcomes.
• Experience, although a good teacher, results in
  conclusions about care that contain bias

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Scientific Approach

• Research evidence provides a scientific basis for
  nursing practice.
• A scientific approach to clinical decision-making
  results in a practice with known cause and
  effect and predictable outcomes.

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Types of Research Studies

• Single research studies
• Randomized Controlled Trials (RCTs)
• Descriptive studies
• Evidence summaries
• Systematic reviews
• Meta-analysis
• Integrative reviews

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Finding Evidence

• What counts as evidence?
• RCTs
• Systematic reviews
• Meta-analysis
• Quasi-experimental
• Prospective cohort studies
• Case-control studies
• Cross-sectional surveys
• Correlational studies
• Qualitative studies
• Retrospective vs. Prospective

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Formulate question to guide search

• Break question down into searchable components
• PICO formula
• Patient population/problem
• Intervention or exposure
• Comparison
• Outcome

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Retrieve relevant evidence effectively

• Textbook
• Journal
• Bibliographic database (MEDLIBE, CINAHL)
• Evidence-based journal series
• Systematic reviews (Cochrane Library, STTI Online
  Journal)
• Evidence-based clinical practice guidelines
• AHRQ
• National Guideline Clearinghouse
• U. S. Preventive Services task Force
• Internet

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Designs that produce the best evidence

• Treatment (interventions)
• RCTs
• Systematic reviews
• Meta-analyses
• Diagnosis (screening assessment)
• Positive negative ratios of diagnostic tests
• Prognosis (nature of the disease)
• Prospective cohort studies
• Causation (risk or harm)
• Cohort studies
• Case-control studies

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Evaluating info on the internet

• Are you PLEASED with the site?
• Purpose
• Links
• Editorial
• Author
• Site
• Ethical
• Dates

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Evaluating evidence

• Who is qualified to judge?
• Clinical experts
• Methodology experts
• Other stakeholders

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Variables thought to affect quality of evidence

• Sample selection
• Randomization
• Blinding
• Sample size
• Description of intervention

• Outcomes
• Length of follow-up
• Attrition
• Confounding variables
• Statistical analysis

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Strength of evidenceBradford-Hill Criteria for
Causation

• Temporality
• Strength
• Dose-response
• Reversibility
• Consistency
• Biologic plausibility
• Specificity
• Analogy

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Presenting Evidence to the Patient
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• The patient has a choice

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The last patient
Other professionals
Experience
The media
Litigation
Provider
Patient
Resources
Education
Friends relatives
Resources
Audit
Evidence
Evidence
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Elements of face-to-face decision-making

• Information given by nurse
• Interpretation by patient
• Discussion between nurse and patient

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Providing information

• Finding research evidence
• Systematic appraisal
• Probability that pt will benefit
• magnitude of benefit
• probability that pt will have adverse effects of
  intervention
• magnitude of adverse effects

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Patient Interpretation

• Pt may need time to think
• Educational pamphlets
• Pt will interpret in two ways
• How evidence appears to him/her
• How outcome of intervention correlates with
  his/her values

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Discussion between patient nurse

• Nurse/patient relationship
• How evidence is presented
• Confidence demonstrated by nurse
• Time