Clinical Trials

Question 1

PHASES OF CLINICAL TRIALS

Answer 1

Phase I: toxicity documented
Phase II: evaluate effect, estimate adverse events
Phase II: randomize
Phase IV postmarketing survey

Question 2

EFFICACY VS EFFECTIVENESS

Answer 2

what the intervention accomplishes in ideal setting
vs
what it accomplishes in real world

Question 3

SAMPLE SIZE

Answer 3

consider effect size, significance level, power

Question 4

EFFECT SIZE

Answer 4

represented as ratio (relative risk, risk ratio, hazard ratio, difference)
the smaller the effect size, the larger the sample size required

Question 5

SIGNIFICANCE LEVEL ⍺

Answer 5

usually set at 5% (o.05)
chance of finding an effect when one dose not exist
(false positive or type I error)

Question 6

POWER (1- β)

Answer 6

usually set at 80-90%
ability to detect an effect when it exists.
β is the chance of concluding there is no difference when one exists (false negative or type II error)

Question 7

FEASIBILITY

Answer 7

can sufficient patients be recruited in time frame to meet targew3t