Calculator for EPV
Version 1.12 Revised: 2001-12-10
You can calculate Etiologic Predictive Value (EPV) by entering:
The sensitivity of the test.
Theta, i.e. the relation between the proportion of positive tests in a healthy control population and in a population of symptomatic carriers. The value 1.0 is suggested and will be appropriate for most situations.
The number of positive and negative tests obtained in the group of symptomatic patients.
The number of positive and negative tests obtained in a healthy control population.
The numbers already filled in is an example of evaluating a throat culture used during summer season in children 3-15 years of age1. Press "Calculate" to see EPV being calculated. Then alter the numbers to fit your situation and press "Calculate".
This calculator works off line. You can save this webpage on your computer as a file and run it without being connected to the internet. However, it is advisable to check for updated versions once or twice a year.
Ronny Gunnarsson MD PhD
Department of Primary Health Care
Back to Main menu