Public health

Question 1

Sensitivity

Answer 1

TP/(TP + FN)

TP = true positive
FN = false negative.      OR.        1 - FN

Sensitive asks “what percentage in which it picks up a true positive or negative”

Sensitive detects true positive

Question 2

Specificity

Answer 2

TN/(TN + FP) OR 1 - FP

TN = true negative
FP = false positive

Detects true negatives

Question 3

Positive predictive value

Answer 3

TP/(TP + FP)

Question 4

Negative predictive value

Answer 4

TN/(TN + FN)

Question 5

Prevalence

Answer 5

(TP + FN)/(TP + FP + TN + FN)

POSITIVE VALUES/TOTAL VALUES

Question 6

Odds Ratio

Answer 6

(People with risk factor that have the disease/people with risk factor that DONT have the disease)

DIVIDED BY

(people without risk factor that have the disease/people without risk factor that DONT have the disease)

Question 7

Relative risk

Answer 7

(% of people with risk factor that develop the disease/% of people WITHOUT risk factor that develop the disease)

R = 1 indicates no association
R > 1 indicates increased association between risk factor and disease development
R < 1 indicates decreased association between risk factor and disease development

Question 8

Attributable Risk

Answer 8

(% of people with risk factor that develop the disease) - (% of people WITHOUT risk factor that develop the disease)

What’s attributable to the risk factor

Question 9

Relative Risk Reduction

Answer 9

RRR = 1 - RR

Question 10

Absolute Risk Reduction

Answer 10

(% of people WITHOUT risk factor that have the disease) - (% of people WITH risk factor that have the disease)

Question 11

Number needed to treat

Answer 11

NNT = 1/ARR

Lower # = better benefit

Question 12

Number needed to harm

Answer 12

NNH = 1/AR

Higher # = safer exposure