Random facts (epidemiology, etc) Flashcards

1
Q

Define sensitivity

A
  • The likelihood of a positive test result in a patient affected with the disease (a true positive)
  • Higher the sensitivity, the lower the false negative rate (so if they test negative, it’s believable)
  • Used to RULE OUT a disease (screening test)
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2
Q

Define specificity

A
  • The likelihood of a negative test result in a patient not having the disease (true negative rate)
  • Higher the specificity, the lower the false positive rate (so if they test positive, it’s believable)
  • Used to CONFIRM a diagnosis
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3
Q

Define positive predictive value

A
  • The chance that a patient with a positive test result has the disease
  • Good confirmatory tests
  • Usually correlates with specificity when the disease prevalence is low
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4
Q

Define negative predictive value

A
  • The change that a patient with a negative test result does not have the disease
  • Good screening tests
  • Usually correlates with sensitivity when the disease prevalence is high
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5
Q

What do PPV and NPV depend on?

A

Disease prevalence

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