(6) Blood pressure lowering and stroke prevention Flashcards
What is an allocation bias?
If there is a difference in how participants are selected for a group this is known as alloaction bias
What is selection bias?
The bias introduced by the selection of individuals, groups or data for analysis in such a way that proper randomization is not achieved
What is a run in phase?
Where potential research participants are tested to see their compliance to the procedure. This is carried out by providing a set of instructions and monitering to see if they adhear to the regime
What is the purpose of the run in phase?
- Ensure disease state is stable
- Identify those with conditions requiring clinical intervention
- Individual unable to comply
When is a parallel group design used?
When effect of treatment is not reversible
When is a cross over design used?
- When effect of treatment is reversible & not taken for extended period of time
- Condition is (reasonably) stable
What is standard error?
Standard deviation
What are carry over effects?
When doing a cross over there may be residual influences on the data from the previously allocated group
How is compliance maxomised in a cohort study?
1) selection of patients (not too ill)
2) double blind design
3) run-in period where all get treatment
(identifies those who can’t tolerate it or unlikely to comply)
What is per protocol?
Expluding patients who were not compliant to the treatment
What is as treated?
Where you move a person who is not complying to the group they best fit (e.g. not taking medication put them in the control)
What is intention to treat?
Where you leave the non compliant particapents in their group and accept that non compliance is a natural process in society
