Enter the number of true positives and false positives into the calculator to determine the Positive Predictive Value (PPV) of a diagnostic test.
Positive Predictive Value Formula
The following formula is used to calculate the Positive Predictive Value (PPV).
PPV = (TP / (TP + FP)) * 100
Variables:
- PPV is the Positive Predictive Value (%)
- TP is the number of true positives
- FP is the number of false positives
To calculate the PPV, divide the number of true positives by the sum of true positives and false positives, then multiply by 100 to get the percentage.
What is Positive Predictive Value?
Positive Predictive Value (PPV) is a measure of the performance of a diagnostic test or screening method. It represents the probability that a person who has a positive test result actually has the disease. A higher PPV indicates that the test has a lower rate of false positives and is more reliable when it gives a positive result.
How to Calculate Positive Predictive Value?
The following steps outline how to calculate the Positive Predictive Value (PPV).
- First, determine the number of true positives (TP).
- Next, determine the number of false positives (FP).
- Use the formula PPV = (TP / (TP + FP)) * 100.
- Finally, calculate the Positive Predictive Value (PPV) in percentage.
- After inserting the variables and calculating the result, check your answer with the calculator above.
Example Problem :
Use the following variables as an example problem to test your knowledge.
True Positives (TP) = 80
False Positives (FP) = 20