Clinical Epidemiology 5: Risk: Exposure to Disease

Question 1

Clinical studies in which researcher gathers data by simply observing events as they happen without playing an active part

Answer 1

Observational studies

Question 2

A group of people who have something in common when they first asembled and who are then observed for a period of time

Answer 2

Cohort

Question 3

Three criteria needed to be fulfilled to observe a cohort properly

Answer 3

1. All do not have desired outcome or disease at the time they are assembled
2. Observed over meaningful amount of time (sufficient time)
3. All should be observed over the full period. Dropouts should be accounted for.

Question 4

Basic design of cohort study

Answer 4

Divide cohort into exposed and unexposed, then see who develops disease or desired outcome at the end

Question 5

Incidence study is another name for what type of study design?

Answer 5

Cohort study

Question 6

Risk measurement measuring probability of an event in a population under study

Answer 6

Absolute Risk

Question 7

Formula for absolute risk

Answer 7

New cases in giveb period of time / number of people.

Formula similar to incidence

Question 8

Additional risk of disease following exposure above that experienced by unexposed population

Answer 8

Attributable Risk (or Risk Difference)

Question 9

Formula for attributable risk

Answer 9

Incidence in Exposed - Incidence in Unexposed

Question 10

Number of times more likely exposed persons get a disease compared to unexposed persons

Answer 10

Relative Risk

Question 11

Formula for relative risk

Answer 11

Incidence in exposed / incidence in unexposed

Question 12

It measures excess incidence of a disease in a community attributable to a risk factor

Answer 12

Population attributable risk

Question 13

Formula for population attributable risk

Answer 13

Attributable risk x prevalence of exposure to risk factor in population

Question 14

Fraction of disease occurrence in a population associated with a risk factor

Answer 14

Population attributable fraction

Question 15

Formula for population attributable fraction

Answer 15

Population attributable risk / Total Incidence

Question 16

Variables part of the system being studied but are not the exposure or primary disease of interest

Answer 16

Extraneous Variables / Covariates

Question 17

Comparison of two naturally occuring groups, exposed and unexposed without implying that the exposure was responsible for differences in outcome

Answer 17

Crude Measures of Effect

Question 18

A variable associated with both the exposure and disease but is not part of the causal chain from exposure to disease

Answer 18

Confounding Variable / intermediate outcome

Question 19

Any process aimed at removing the effects of extraneous variables while examining independent effects of individual variables.

Answer 19

Controlling