Prevalence
Prevalence is the true proportion of a disease in a population.
Prevalence equals the sum of the false negatives plus the true positives divided by the sum of the false negatives and positives and the true negatives and positives.
Formula
![QuantityVariable["prev", "Unitless"] == (QuantityVariable["fn", "Unitless"] + QuantityVariable["tp", "Unitless"])/(QuantityVariable["fn", "Unitless"] + QuantityVariable["fp", "Unitless"] + QuantityVariable["tn", "Unitless"] + QuantityVariable["tp", "Unitless"])](https://www.wolframcloud.com/objects/resourcesystem/marketplacestorage/resources/e32/e32e1f2d-bf6d-46f5-9db7-0ba81452b00c/Webpage/FormulaImage.png "Copy to Clipboard")
| symbol | description | physical quantity |
|---|---|---|
| prev | prevalence | "Unitless" |
| fn | false negatives | "Unitless" |
| tp | true positives | "Unitless" |
| fp | false positives | "Unitless" |
| tn | true negatives | "Unitless" |
Forms
Examples
Get the resource:
| In[1]:= | ![ResourceObject["Prevalence"]](images/e32/e32e1f2d-bf6d-46f5-9db7-0ba81452b00c-io-1-i.en.gif){kind=small} |
| Out[1]= |  |
Get the formula:
| In[2]:= | ![FormulaData[ResourceObject["Prevalence"]]](images/e32/e32e1f2d-bf6d-46f5-9db7-0ba81452b00c-io-2-i.en.gif){kind=small} |
| Out[2]= |  |
Use some values:
| In[3]:= | ![FormulaData[
ResourceObject[
"Prevalence"], {QuantityVariable["fn","Unitless"] -> 2,
QuantityVariable["fp","Unitless"] -> 3}]](images/e32/e32e1f2d-bf6d-46f5-9db7-0ba81452b00c-io-3-i.en.gif){kind=small} |
| Out[3]= |  |