Study your flashcards anywhere!

Download the official Cram app for free >

  • Shuffle
    Toggle On
    Toggle Off
  • Alphabetize
    Toggle On
    Toggle Off
  • Front First
    Toggle On
    Toggle Off
  • Both Sides
    Toggle On
    Toggle Off
  • Read
    Toggle On
    Toggle Off
Reading...
Front

How to study your flashcards.

Right/Left arrow keys: Navigate between flashcards.right arrow keyleft arrow key

Up/Down arrow keys: Flip the card between the front and back.down keyup key

H key: Show hint (3rd side).h key

A key: Read text to speech.a key

image

Play button

image

Play button

image

Progress

1/33

Click to flip

33 Cards in this Set

  • Front
  • Back
What would a 100% sensitive test do?
Always detect disease when present
What would a 100% specific test do?
Always exclude disease when absent.
How is diagnostic testing different from screening?
-Diagnostic tests symptomatic individuals
-Screening tests individuals before symptoms start
What is the purpose of doing a diagnostic test?
To move the estimated probability of disease toward either end of the probability scale.
When setting up a calculation chart for diagnostic testing:
-What goes on the y axis
-x axis?
Y = test pos or neg
X = actual disease pos or neg
Define sensitivity:
The probability that a person with the disease will have a positive test.
Formula for sensitivity:
A/A+C
What is specificity?
The probability that a person without the disease will have a negative test.
Formula for specificity:
TN / TN + FP
What is PPV?
Pos predictive value - the probability of DISEASE given a pos test result
What is NPV?
Probability of NOT having disease given a neg test result
Formula for PPV/NPV
PPV = A/A+B
NPV = D/C+D
Changing Prevalence of a disease affects what?
NPV and PPV - not sensitivity or specificity
So PPV/NPV depend on:
-Sensitivity
-Specificity
-Prevalence
Prevalence formula:
A + C
------
Total
How do PPV and NPV change when you increase disease prevalence?
PPV goes up as prevalence does
NPV goes down
Screening tests are for
Asymptomatic individuals
Diagnostic tests are for
Symptomatic individuals
What is Bayes' theorem?
The PPV of a test given a certain prevalence.
If a disease is rare, prevalence is low in a population, what will you see more of?
Falsely positive tests
What is Primary Prevention?
-Give an example
Measures to prevent disease from occurring; an example is vaccination.
What is 2ndary prevention?
-Give an example
Early identification of disease to prevent progression or reduce disability
-Mammography
What is Tertiary prevention?
Treatment or rehab once a disease has occurred, to minimize sequelae or recurrence.
When is primary prevention appropriate?
Before the true onset of disease
When is secondary prevention appropriate?
Between the true onset of disease and clinical onset.
When is tertiary prevention appropriate?
After the clinical onset of disease, but before late stages.
Mammography, clinical breast exams, and self breast exams are:
2ndary prevention techniques to detect developing breast cancer.
What type of prevention is BRCA genetic screening considered?
Primary
What is Tamoxifen?
Tertiary
What are the first 2 criteria for an effective screening test that have to do with the disease itself?
1. Morbidity/Mortality must be of sufficient concern to public health
2. Disease prevalence sufficient
What 2 criteria for an effective screening test have to do with the test?
1. The test must be sufficiently sensitive and specific
2. The test must be safe and acceptable
What 2 criteria for an effective screening test concerns the diagnostic workup?
The workup must be acceptable given the number of false positives.
Most important riteria for an effective screening test:
Pre-clinical intervention must improve outcomes.