Analytic Epidemiology

Question 1

What is Attributable Rate/Risk (AR); Rate/Risk Difference

Answer 1

ID exp – ID unexp
CI exp – CI unexp

Question 2

The rate or risk difference estimates the excess (rate/risk) of disease among the exposed attributable to the exposure.

If we assume causation, we could interpret it as: “X cases of disease per XXXX people could have been prevented by eliminating the exposure among the exposed group”

Answer 2

Attributable; rate/risk (AR); Rate/Risk Difference

Question 3

Attributable risk %

Answer 3

Among the exposed,If we assume causation, X% of the deaths among the exposed is attributable to the exposure
OR
If we assume causation, X% of the cases in the exposed group would have been prevented by eliminating the exposure.

Question 4

Population Attributable Risk/Rate (PAR) or Population Rate/Risk Difference

Answer 4

The population rate or risk difference estimates the excess rate/risk of disease in the total population that is due to the presence of the exposure in the population.

Question 5

Population Attributable Risk/Rate Percent = Etiologic Fraction among the Population

Answer 5

If we assume causation, , X% of cases of disease in the total population (i.e., not just among the exposed) is attributable to the exposure
OR
If we assume causation, X% of the cases of disease in the total population could have been prevented by eliminating the exposure.

AR is in reference to those exposed whereas PAR referencing the total pop

Question 6

Number Needed to Treat

Answer 6

X people (i.e., number of people) need to be treated in order to prevent the outcome in 1 person.

1 / (CI exp – CI unexp)