Sensitivity and Specificity

Question 1

look at this fun little thing

Answer 1

pretty colors

Question 2

Sensitivity

Answer 2

% of individuals with the disease who were positive to the test (+ of the sick)

How good is your test at finding cases?

Question 3

Specificity

Answer 3

% of non-disease subjects who were negative to the test (- in the healthy)

How good is your test at ruling out non-cases?

Question 4

Equation for False Negative

Answer 4

1 - sensitivity

Question 5

Equation for False Positive

Answer 5

1 - specificity

Question 6

Sensitivity Equation

Answer 6

Question 7

Specificity Equation

Answer 7

Question 8

High Cutoff between groups?

Answer 8

few false positives but lots of false negatives
low sensitivity and higher specificity

Question 9

Low Cutoff between groups?

Answer 9

few false negatives but a whole lot of false positives
high sensitivity and low specificity

Question 10

Series Testing

Answer 10

use of two sequential tests to retest the POSITIVES

Question 11

Parallel Testing

Answer 11

use of two sequential tests to retest the NEGATIVES

Question 12

Effect of Series Testing on Sensitivity and Specificity

Answer 12

increases SPECIFICITY

Question 13

Effect of Parallel Testing on Sensitivity and Specificity

Answer 13

increases SENSITIVITY

Question 14

3 Determinants of Predictive Value

Answer 14

1. Sensitivity
2. Specificity
3. Prevalence

Question 15

positive predictive value

Answer 15

probability of disease in a subject with a positive test result

Question 16

negative predictive value

Answer 16

probability of not having the disease with a negative test result

Question 17

Relationship of Prevalence to Predictive Values

Answer 17

prevalence close to 0 –> PPV = 0
prevalence close to 100% –> NPV = 0

Question 18

Cute Calc Summary

Answer 18

so much math