consider [1 mark]:
a) The strength of the association between an exposure and the outcome
b) Evidence that the exposure of interest has appeared before the outcome.
c) Evidence showing that reductions in the exposure level will reverse the risk of the outcome.
d) A, B and C
e) A and B only
V. A double-blind study was designed to test the efficacy of a drug. One group of the patients consisting of 1227 participants were given a placebo and the other group of patients consisting of 1220 were given the active drug. Both groups were to be followed up for one year. After 6-months of the trial, 35% of participants in the placebo groups dropped out of the study and 4% of the participants taking the active drug dropped out of the study. What is the SINGLE BEST explanation for this occurrence [1 mark]?
a) Failure of the active drug
b) Insufficient information to interpret data
c) Systematic error
d) Chance event
e) Breakdown of the double-blind study
VI. The highest level of evidence provided for cancer treatment usually comes from: [1 mark]
a) Randomised control trials
b) Phase II clinical trials
c) Phase III clinical trials
d) Systematic reviews of observational studies
e) Meta-analyses of intervention studies