Formulas for final

Question 1

Attributable Risk

Answer 1

AR= Incidence in exposed - Incidence in unexposed

A/(A+B) - (C/(C+D

Question 2

Attributable Proportion or Percent

Answer 2

[(Incidence in exposed - incidence in unexposed) / incidence in exposed] x 100

Question 3

Population Attributable Risk

Answer 3

Cumulative incidence in total population - cumulative incidence in unexposed

Question 4

Population Attributable Risk

Answer 4

[(Cumulative incidence in total population - cumulative incidence in unexposed) / cumulative incidence in total population] x 100

Question 5

Odds ratio

Answer 5

AD/BC

Question 6

Relative Risk (RR)

Answer 6

Cumulative incidence among exposed / cumulative incidence among unexposed

A/(A+B)
————
C /(C+D)

Question 7

Sensitivity

Answer 7

The ability of the test to correctly identify who has the disease; it’s the proportion of true positivity over everybody with the disease (or the total of first column)

A / (A+C)

Question 8

Specificity

Answer 8

The ability to identify who does not have a disease; the proportion of true negatives over everybody is no does not have the disease

D / (B+D)

Question 9

Positive predictive value (PPV)

Answer 9

Given the test is positive, what proportion have disease; it’s true positives over everybody who tested positive

A / (A+B)

Question 10

Negative predictive value (NPV)

Answer 10

Given the test is negative, what proportion are without disease; it’s true negatives over everybody who tested negative

D / (C+D)