Screening: statistics Flashcards Preview

BMS1042: Public health > Screening: statistics > Flashcards

Flashcards in Screening: statistics Deck (10)
Loading flashcards...
1
Q

disease present and positive test

A

true positive

2
Q

disease present and negative test

A

false positive

3
Q

disease absent and negative test

A

true negative

4
Q

disease absent and positive test

A

false negative

5
Q

SENSITIVity

A

probability of disease present and positive test (true positive) / disease present

6
Q

SPECIFICity

A

probability of disease absent and negative test (true negative) / disease absent

7
Q

describe relation of sensitivity and specificity to prevalence

A

sensitivity is looking at DISEASED only
specificity is looking at HEALTHY only
–> no overlap

furthermore the test will give the same proportion within diseased/healthy groups, regardless of their size

8
Q

positive predictive value

A

probability of disease present and positive test (true positive) / positive test

9
Q

negative predictive value

A

probability of disease absent and negative test (true negative) / negative test

10
Q

describe relation of PPV and NPV to prevalence

A

within each, both diseased and healthy individuals are looked at.

therefore, change in prevalence will result in change to proportions and therefore PPV and NPV