Evidence Based Medicine Flashcards
What are the levels of evidence in the evidence pyramid?
Editorials, expert opinion Case series, case reports Case-control studies Cohort studies Randomised controlled trials Systematic reviews
What is a systematic review?
A review of evidence that uses a systematic review to identify, select and critically appraise relevant primary research
What can trials assess?
Drugs
Surgery
Types of management
Educational interventions
What does a randomised controlled trial mean?
Randomised = the population receiving the intervention and the population being compared are only different due to random variation Controlled = Intervention is being compared to something else e.g. placebo, gold standard Trial = An experimental intervention
Why should trials be random?
It prevents differences between groups affecting the outcome, it stops the experimenter choosing who gets treatment and so ultimately it removes bias
What are some confounding variables?
Illness severity at entry Current treatment Disease duration Previous medical history Age
What are some factors that would exclude people from a trial?
Clear preference for intervention or control by the patient or the doctor
If the patient is unlikely to adhere to treatment
What are some factors that would include patients from a trial?
Likely to benefit from the treatment - definetly has the disease and is likely to respond to treatment
Unlikely to be harmed by the treatment
What are some controls that can be used in a trial?
Placebo
Nothing
Current best practice
Standard care
What are some factors that need to be present to measure the outcome?
Clinically relevant
Easily measured
Accurately measured
Specified in trial protocols
What are some problems associated with measuring outcomes?
Losing patients due to emigration, death or voluntary withdrawal
What is a confounding variable?
It occurs when the association between an exposure and an outcome is in fact the result of another variable
