EBM Flashcards
Give examples of types of outcome measures in trials
surrogate markers
stage / extent of disease
patient -orientated outcomes
Give examples of surrogate markers of disease
HbA1c
cholesterol
blood pressure
Give examples of stage / extent of disease outcomes
diabetic ulcers
angiographic CAD
stroke
Give examples of patient- orientated outcomes
mobility suffering longevity morbidity mortality
What does bias affect?
Accuracy
What does variability assess?
precision
What types of randomisation are there?
simple
blocking
stratification for important baseline criteria
What are some alternatives for randomisation?
historical controls non-randomised concurrent controls different treatment per physician systematic alternation of treatments sources of bias in these need to be considered
What is meant by the placebo effect?
response to medical intervention which results from the intervention itself, not from the specific mechanism of the intervention
What are the advantages of cross over trials?
variation is only subject to within subject variability not between
smaller sample size needed
What are the disadvantages of crossover trials?
strict assumption about carry-on effects
inappropriate in diseases that may be cured
drop outs before second period
What are the advantages of factorial designs?
of no interaction, can perform two experiments with fewer patients
can examine interactions
What are the disadvantages of factorial design?
added complexity
adverse effects due to poly-pharmacy
What are some of the barriers to partcipation in clinical trials?
unaware of them lack of access fear, distrust and suspicion of research have practical or personal obstacles be unwilling to go against phyicians' wishes
What are the benefits of participating in clinical trials?
at a minimum, the best standard of treatment
early access to new treatment s
participation in enhancing medical knowledge
active role in own health care
the medical team conducting the trial will carefully and regularly monitor the patient’s progress
