Lecture 4: Clinical trials in CVD Flashcards
1
Q
Define a clinical trial
A
longitudinal study that can assess an INTERVENTION and measure changes in the INCIDENCE of an outcome
involves a control group
2
Q
Key outcomes of clinical trials?
A
relative risks and hazard ratios
absolute risk/rate reduction
number needed to treat
survival analysis
3
Q
Ratiomale for randomisation?
A
-reduce confounders
4
Q
Rationale for blinding?
A
- reduce observer bias
5
Q
Can cross over (parallel) be a source of selection bias?
A
Yes
- if subjects leave group because of drug side effects = healthy group on active drug
- perceived effect of active drug better than placebo
6
Q
What is intention to treat? What is its purpose?
A
Assumes all subjects remained in original group
Aims to reduce selection bias
7
Q
T/F intention to treat overestimates Tx effect?
A
F - it underestimates Tx effect
