Some Concepts for Considering Evidence

Some Concepts for Considering Evidence-based Veterinary Medicine
JM Gay DVM PhD DACVPM 10/14
Approximately half of prevention and treatment
interventions for important human clinical
conditions are not supported by strong empirical
evidence.
11%
23%
51%
http://www.cochrane.org/faq/it-estimated-only-10-35medical-care-based-rcts-what-information-based
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2071976/
7%
http://www.researchgate.net/post/What_proportion_of_medic
ine_is_evidence-based
Literature
Databases
The strongest evidence is at the limited tip of the Strength Pyramid
http://guides.library.yale.edu/content.php?pid=9786&sid=73113
Medical error is frequent
http://en.wikipedia.org/wiki/To_Err_is_Human
The cycle of scientific knowledge production to publication to practitioner access is years long
http://www.unm.edu/~unmvclib/handouts/sciencepublicationchart.pdf
Given the situation in human medicine, what is the likely situation in veterinary medicine?
Definitions – modified from http://www.vetmed.wsu.edu/courses-jmgay/GlossClinEpiEBM.htm:
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Dogma: Those beliefs held as established or put forth as an authoritative or expert opinion, often contained in a secondary or tertiary
source, without linkage to supportive empirical evidence from primary sources. Medical dogma may be derived from unevaluated
biological hypotheses, analogical reasoning, or uncritical observation or experience without recognition of the effects of chance, natural
biological variation, and observer bias. A significant portion of medical practice is dogma unsupported by empirical evidence. Repetition
across secondary and tertiary sources or the number of people, whatever their qualifications, that hold a belief does not change its
status. Because of time and space limitations, class lectures, class notes, and textbooks present information as dogma.
Evidence: That which supports, manifests, or shows that something is the case. Depending on how it was obtained, evidence varies
greatly in strength. Note that evidence can be valid but that a theory the evidence is alleged to support can still be wrong.
Empirical Evidence (Facts): Knowledge obtained by looking rather than reasoning or feeling. In the scientific sense, the objective
findings derived from the analysis but not interpretation of objective data obtained by performing formal observational or experimental
procedures that are repeatable (verifiable) and that meet currently accepted standards for design, execution, and analysis. The strongest
empirical evidence is obtained from rigorous methods incorporated into an experiment designed to have a clear, unequivocal supporting
or refuting outcome. Empirical evidence is weakened by the degree of opportunity for other explanations to account for the findings.
Evidence-based (population-based) medicine (EBM): "An approach to practice in which the clinician is aware of the evidence in
support of their clinical practice and the strength of that evidence" (McMaster). EBM is the use of systematic observation of the clinical
patient and the rules for empirical evidence to critically appraise and interpret information from clinical research (causation, prognosis,
diagnostic tests, and treatment strategies) to apply to that individual patient. The goal of EBM is to increase the likelihood of a better
clinical outcome for an individual patient because of making better clinical decisions and doing so in a more efficient, cost-effective
manner. EBM goes beyond the traditional focus on reasoning based on microbiology, pathophysiology, and pharmacology, beyond the
traditional reliance on authority or expert opinion (dogma) and beyond the traditional use of uncritically and unsystematically evaluated
clinical experience (JAMA 268:2420-2425 (1992), BMJ 310:1122-1126 (1995), J Royal Soc Med 88:620-624(1995)).
Selected Materials for Further Information:
• Knowing what isn't so: Evidence-based medicine- http://www.vetmed.wsu.edu/courses-jmgay/documents/ResearchEBM.pdf
• Clinical study design tree - http://www.vetmed.wsu.edu/courses-jmgay/documents/ClinicalDesignTree.pdf
• Considerations on Medical Error from an Epidemiologist’s Perspective - WSU Common Reading Program presentation
http://www.vetmed.wsu.edu/courses-jmgay/documents/WSURdngPgm14.pdf
• Vet Clin 576 - Introduction to Clinical Research - http://www.vetmed.wsu.edu/courses-jmgay/ClinicalResearchIntro.htm
Representative On-line EBM Sources:
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CEBM – Center for Evidence-based Medicine, U Oxford - http://www.cebm.net/?o=1011
CEVM – Centre for Evidence-based Veterinary Medicine - http://www.nottingham.ac.uk/CEVM/Index.aspx
EBVMA Evidence-based Veterinary Medicine Association- http://www.ebvma.org/
EBP - Evidence-based practice – UW Health Sciences Library - http://libguides.hsl.washington.edu/ebp
Introduction to Evidence-based Practice – Duke - http://guides.mclibrary.duke.edu/content.php?pid=431451&sid=3529491
The Cochrane Collaboration - http://www.cochrane.org/
Books:
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Cockcroft P, MA Holmes (2003). Handbook of Evidence-Based Veterinary Medicine
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Fletcher, RH & SW (2014). Clinical Epidemiology: The essentials, 5 ed.
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Hayes RB, et al. (2005). Clinical Epidemiology: How to do clinical practice research, 3 ed.
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Hulley SB et al. (2013). Designing Clinical Research: An epidemiologic approach, 4 ed.
Buczinski S et al. (2012). Evidence-based Veterinary Medicine for the Bovine Veterinarian. Veterinary Clinics of North America: Food
Animal Practice 28(1)
Ramey DW (2007). Evidence-based Veterinary Medicine. Veterinary Clinics of North America: Equine Practice 23(2)
Schmidt, PL (2007). Evidence-Based Veterinary Medicine. Veterinary Clinics of North America: Small Animal Practice 37(3)
Wikipedia:
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Evidence-based medicine - http://en.wikipedia.org/wiki/Evidence-based_medicine
Evidence-based practice - http://en.wikipedia.org/wiki/Evidence-based_practice
Medical error - http://en.wikipedia.org/wiki/Medical_error
Cognitive bias - http://en.wikipedia.org/wiki/Cognitive_bias
Cognitive bias mitigation - http://en.wikipedia.org/wiki/Cognitive_bias_mitigation
Empirical evidence - http://en.wikipedia.org/wiki/Empirical_evidence
Validity (statistics) - http://en.wikipedia.org/wiki/Validity_(statistics)
Objectivity (science) - http://en.wikipedia.org/wiki/Objectivity_(science)
Scientific method - http://en.wikipedia.org/wiki/Scientific_method
Philosophy of science - http://en.wikipedia.org/wiki/Philosophy_of_science