8 February 2012, 12:30-13:10
A journey into bioclinical evidence: from bench...
to bedside... to population
Giuseppe Biondi [email protected]
Learning goals
• Goals of bioclinical research and evidence hierarchy
• Primary research
• Secondary research
Why collaboration is needed?
CLINICIAN
BASIC SCIENTIST
How to implement collaboration
Learning goals
• Goals of bioclinical research and evidence hierarchy
• Primary research
• Secondary research
Goals of bioclinical research
• Increase knowledge
• Improve decision making
• Improve process efficiency
• Improve clinical outcomes
These goals are (hopefully) fulfilled by accumulating bioclinical evidence
Final aim is causal inference
Final aim is causal inference• Does the association make biological sense?• Is there a dose-response gradient?• Is the temporal association correct?• Is the association specific?• Is there evidence from true experimentation in
humans?• Is the association strong?• Is the association consistent from study to study?
Sir Austin Bradford Hill
What about evidence-based medicine?
What about evidence-based medicine?
Excerpt from a 1990 leaflet for internal medicine resident at McMaster University (Hamilton, Canada):
“…goal of evidence-based medicine is to be aware of the evidence on which one’s practice is based, the soundness of the evidence, and the strength of inference the evidence permits.
The strategy employed requires a clear delineation of the relevant question(s); a thorough search of the literature relating to questions; a critical appraisal of the evidence, and its applicability to the clinical situation; and a balanced application of the conclusions to the clinical problem.”
Guyatt and Rennie, Users’ guide to the medical literature, 2002
Evidence-based medicine (EBM)
Definition:
The coscientious, explicit, and judicious use of current best evidence in making decisions about the care of individual patients.
The practice of evidence-based medicine requires integration of individual clinical expertise and patient preferences with the best available external clinical evidence from systematic search.
Guyatt and Rennie, Users’ guide to the medical literature, 2002
Rebuttal to critics of EBM
Evidence alone is never sufficient to
make a clinical decision:
decision makers must always trade the benefits and
risks, inconvenience, and costs associated with
alternative management strategies, and in doing so
consider the patient’s values!
Guyatt and Rennie, Users’ guide to the medical literature, 2002
EBM hierarchy of evidence1. N of 1 randomized controlled trial
2. Systematic reviews of randomized trials
3. Single randomized trial
4. Systematic review of observational studies addressing patient-important outcomes
5. Single observational study addressing patient-important outcomes
6. Physiologic studies (eg blood pressure, cardiac output, exercise capacity, bone density, and so forth)
7. Unsystematic clinical observations
8. Non-clinical studiesGuyatt and Rennie, Users’ guide to the medical literature, 2002
Other evidence hierarchies
Evans, J Clin Nurs 2003
Learning goals
• Goals of bioclinical research and evidence hierarchy
• Primary research
• Secondary research
Bench: in vitro study
Nührenberg et al, Cardiovasc Res 2008
Bench: animal study
Abbate et al, Circulation 2008
Biondi-Zoccai et al, Catheter Cardiovasc Interv 2011
Bedside: case report
Bedside: case series
Biondi-Zoccai et al, Int J Cardiol 2007
Bedside: cross-sectional study
Herrington et al, Circulation 2004
Bedside: cohort study (registry)
Sangiorgi et al, EuroIntervention 2007
Bedside: case-control study
Guagliumi et al, J Am Coll Cardiol Intv 2012
Bedside: non-randomized cohort study
Biondi-Zoccai et al, Clin Res Cardiol 2011
Bedside: therapeutic randomized trial
Biondi-Zoccai et al, Acta Cardiol 2011
Bedside: diagnostic randomized trial
Ouwendijk et al, ARJ 2008
Learning goals
• Goals of bioclinical research and evidence hierarchy
• Primary research
• Secondary research
Parallel hierarchy of CV research
Biondi-Zoccai et al, Ital Heart J 2003
Qualitative reviews
Systematic reviews
Meta-analyses from individual studies
Meta-analyses from individual patient data
Case reports and series
Observational studies
Observational controlled studies
Randomized controlled trials
Multicenter randomized controlled trials
Meta-analyses can bridge the gap
Biondi-Zoccai et al, HSR Proceedings in Anesthesia and Intensive Care 2011
• What is a systematic review?
– A systematic appraisal of the methodological quality,
clinical relevance and consistency of published
evidence on a specific clinical topic in order to provide
clear suggestions for a specific healthcare problem
• What is a meta-analysis?
– A quantitative synthesis that, preserving the identity of
individual studies, tries to provide an estimate of the
overall effect of an intervention, exposure, or diagnostic
strategy
Bench: qualitative review
Dinarello, Cancer Metastasis Rev 2010
Animal research meta-analyses are feasible and fundable
http://www.nc3rs.org.uk/page.asp?id=864
Bench: study level systematic review and meta-analysis
Biondi-Zoccai et al, Rescuscitation 2003
Bedside: qualitative review
Romagnoli et al, JACC Int 2008
Bedside & population: systematic review (without meta-analysis)
Kip et al, JACC 2008
Bedside & population: study level meta-analysis
Agostoni et al, JACC 2004
Bedside & population: individual patient level meta-analysis
Burzotta et al, Eur Heart J 2009
Bedside & population: network meta-analysis with mixed treatment comparison
Palmerini et al, submtted
• Accumulation of bioclinical evidence is a collective
and cumulative effort
• No hypothesis or project is good or bad at
beginning, but may well or badly planned
• Constructive collaboration between basic
scientists and clinical researchers is pivotal to
succeed
• In my humble opinion, the best researchers are
probably those who can demonstrate their ideas
were wrong (à la Karl Popper)
Take home messages
Thank you for your attention
For any correspondence: [email protected]
For these and further slides on these topics feel free to visit the metcardio.org website:
http://www.metcardio.org/slides.html