Evidence-Based Medicine (EBM) Flashcards
(45 cards)
What is the definition for Evidence-based medicine (EBM) ?
Evidence based medicine is the conscientious, explicit, and judicious use of current best evidence in making decisions about the care of individual patients. (Sackett DL et al, 1996)
What are two examples of experimental study design ?
- Animal and laboratory studies
- Randomised controlled trial (RCT) – Gold standard
What are three examples of observational study designs ?
- Cohort studies
- Case-control studies
- Cross-sectional studies
What does animal research use and what does it test for ?
Animal research uses animals to test potential pharmaceuticals prior to human trials
What are some disadvantages of animal and laboratory studies ?
- Its application is limited considering the difference between human and animal physiology
- Experiments are undertaken in a highly controlled environment
What are the 5 levels of evidence ?
1) randomised controlled trial - prospective, tests treatment. (Secondary, pre-appraised or filtered studies)
2) cohort studies
3) case control studies
4) case report or case series
5) animal and laboratory studies
Why is EBM an important concept for pharmacists ?
- Ensure medicines sold are of high quality, safety and efficacy
- Basis for the recommendations we make to patients and other health professionals through pharmacy services
(It is essential that pharmacists are available to retrieve, appraise and apply research evidence as the basis for clinical decision making)
What does a randomised controlled trial consist of ?
Clinical practice guidelines, meta-analysis, systemic reviews, is prospective and tests treatments.
What do cohort studies involve ?
It is prospective; the cohort has be exposed to a risk. Observe for outcome of interest.
What does case control studies involve ?
It is retrospective ; the subjects have the outcome of interest - you are then looking for the risk factor.
What do case reports and case series contain ?
- narrative reviews
- expert opinions
- editorials
What are the secondary / pre-appraised or filtered studies ?
-clinical practice guidelines
-meta-analysis systemic reviews
What are the primary studies ?
-randomised controlled trial
-cohort studies
-case control studies
Define cross-sectional studies …
How are participants selected ?
- An observational study design where outcomes and exposures are measured concurrently.
Participants are selected based on set inclusion and exclusion criteria.
When is cross-sectional study mainly used ?
In population based research
What is data collected on in a schematic representation of a typical cross-sectional study ?
The data is collected on both outcomes and exposure of the individuals at a given point in time.
What is the case-control study DESIGN ?
Retrospective in nature
What are advantages of a case-control study design ?
- Less expensive
- Easier to do and take less time
- Useful when obtaining follow-up data that is difficult to obtain due to the nature of population being studied
- More efficient if the disease is rare
- This design may be the only ethical way to evaluate something
What are disadvantaged of a case-control study design ?
- Potential recall bias
- Subject to selection bias
- Generally do not allow investigators to calculate an incidence or absolute risk
Is a cohort study prospective or retrospective ?
It is almost always prospective but sometimes can be retrospective cohort studies.
What are the advantages of a cohort study ?
- Can more clearly show the time of exposure and development of the outcome because the subjects are without the disease at baseline.
- Allows for evaluation of more than one outcome as it relates to an exposure
- Allows for the calculation of the incidence
What are the disadvantages of a cohort study ?
- Can be expensive and time consuming because of needing to follow a large number of people
- Loss of follow up can begin to introduce bias
- May not be good for rare diseases
Is a randomised controlled trial (RCT) a prospective study or a retrospective study ?
A prospective study
What are the advantages to a randomised controlled trial (RCT) ?
- Considerers the gold standard
- This design allows for washout of most population bias
- Reduced influence by confounders
- Reduced variability in the outcome(s)
- Easier to blind patients than observational studies