module 2 sensitivity and specificity

Question 1

Sensitivity

Answer 1

The number of positive results for individuals who actually have the disease (true positives)
TP/TP + FN

Question 2

Specificity

Answer 2

The number of negative results for individuals without the disease (true negatives)
TN/FP+TN

Question 3

high sensitivity is good for a

Answer 3

screening test

- low false negatives

Question 4

high specificity is good for a

Answer 4

confirmatory test

- low false positives

Question 5

Positive predictive value

Answer 5

number of people with positive test who actually have the disease
TP/ TP + FP

Question 6

Negative predictive value

Answer 6

number of people with negative test who dont have the disease
TN/ TN + FN

Question 7

NPV and PPV depend on

Answer 7

prevalence of disease

• inc. prevalence -> inc. PPV and Dec. NPV
• inc. prevalence -> dec. FP
• dec. prevalence -> inc. FP

Question 8

Primary prevention

Answer 8

prevention of developing a disease/problem

• immunizations
• seatbelts

Question 9

Secondary prevention

Answer 9

screening

- early detection

Question 10

Tertiary prevention

Answer 10

treatment for a diagnosed disease

- prevent co-morbidities/ secondary problems

Question 11

Prevalence

Answer 11

the burden of a disease in a population at a given time

- captures old and new cases

Question 12

Incidence

Answer 12

number of new cases relative to those at risk

Question 13

Morbidity

Answer 13

incidence rates and prevalence rates are measures of morbidity
- who has the disease

Question 14

Mortality

Answer 14

number of death/numbers at risk x 1000

Question 15

Endemic

Answer 15

local

Question 16

Epidemic

Answer 16

widespread

- a couple countries

Question 17

Pandemic

Answer 17

worldwide