Clinical Trials Flashcards
What is phase 1 of a clinical trial?
Volunteer studies: clinical pharmacology in normal volunteers generating pharmacokinetic, metabolic and pharmacodynamic data
(usually involves around 100 subjects)
What is phase 2 of a clinical trial?
Involves patients: to confirm kinetic and dynamics in patients, provides some evidence of efficacy and identifies likely dosage range and possible side effects (usually involves around 500 subjects)
What is phase 3 of a clinical trial?
Clinical development: formal therapeutic trials where efficacy will be established and evidence of safety obtained, compares new treatment to current best treatment available (usually involves around 1000-3000 patients)
What is phase 4 of a clinical trial?
Post-marketing surveillance: licence granted, to produce evidence of long term safety, carried out when drug has been shown to work, may involve tens of thousands of patients
What are pilot studies?
Not to estimate the outcome but to test study design (time, cost, size)
What is a double blind trial?
- experimental procedure where the subjects of the experiment nor the persons administering the experiment know the critical aspects of the experiment;
- used to guard against both experimenter bias and placebo effects
What is a single blind trial?
-clinical trial in which the researchers but not the subjects know which subjects are receiving the active medication or treatment and which are not: eliminating subjective bias, as the placebo effect, from the test results
What is a prospective trial?
watches for outcomes, such as the development of a disease, during the study period and relates this to other factors such as suspected risk or protection factor(s). The study usually involves taking a cohort of subjects and watching them over a long period. T
What is a retrospective trial?
looks backwards and examines exposures to suspected risk or protection factors in relation to an outcome that is established at the start of the study.
What is a placebo controlled study?
50% subjects given active drug and 50% given the placebo- the outcome is then compared
What is comparison with other therapy?
50% of subjects receive a study drug and 50% receive comparison therapy. Is one bette than the other? is asked
What is a cross-over design?
subjects receive a sequence of different treatments. Compared therapy and study drug are crossed over (wash out period)
What is a randomised control clinical trial?
Patients are assigned at random to either treatment or control
What are some disadvantages of a randomised control clinical trial?
- subjects may not represent general patient population
- twice as many new patients needed for the study
- some physicians will refuse (PFO closure)
- some patients will refuse (will want treatment)
What is a parallel study?
two groups of treatments, A and B, are given so that one group receives only A while another group receives only B. Other names for this type of study include “between patient” and “non-crossover”.
