3) Measures Of Association And Effect

Question 1

Prevalence

Answer 1

Proportion of a population with an attribute of interest at a specified time

Question 2

Incidence

Answer 2

• number of new cases over a period of time

- measure of risk

Question 3

Cumulative incidence

Answer 3

• # of individuals experiencing a new event during a time period / # of susceptible individuals at the beginning of a time period

Question 4

Incidence density

Answer 4

• # of events in time period / person-time of susceptible individuals at risk during a time period

Question 5

Prevalence = ?

Answer 5

Incidence x duration

Question 6

Relative risk

Answer 6

• Incidence in exposed group / incidence in control group

Question 7

Risk difference

Answer 7

Risk in exposed group - Risk in unexposed group

Question 8

NNT

Answer 8

1 / Risk difference

Question 9

Odds ratio

Answer 9

(risk+; Dis+) / (risk- ; Dis +)
_____________________________
(Risk+; Dis -) / (Risk-; Dis -)