# Aetiology and Risk Factors for CVD Flashcards

What is a descriptive research question?

A question which will give a descriptive answer e.g. how common is CHD?

What is an analytical research question?

A question which looks at cause and effect e.g. do lipid-lowering meds decrease the risk of CHD?

What are observational studies?

case series, ecological, cross sectional, case control, cohort

What are interventional studies?

clinical trials

Which study designs are descriptive?

Case series, ecological, cross sectional

Which study designs are analytical?

Case control, cohort, clinical trial

What is a longitudinal study?

involves follow up - information progressively collected over multiple encounters

Which study designs are longitudinal?

Cohort and clinical trials

What is prevalence?

The number of existing cases of a disease or a risk factor at one point in time - it is expressed as a proportion or a percentage

What is incidence?

The number of new cases of a disease or a risk factor over a period of time - can only be drawn from a longitudinal study - expressed as a rate (involves time)

What is risk?

The number of new cases over a defined period divided by the population at risk ???

What is rate?

The number of people who develop a new case divide by total person-time of follow up

What is person-time?

The total number of time of all the people who followed up - e.g. if there were 10 people in a study for 12 months the person-time would be 120 months if everyone was there for the whole time but due to staggered recruitments and drop outs it would be something more like 88 months

What is hazard?

A rate that is updated as the longitudinal study progresses - it is an instantaneous rate

What is an absolute risk/rate?

An isolated measure of risk/rate that does not indicate association with exposure e.g. 5 strokes/10000 men per year