The [[prevalence]] in the population sample is calculated to be:
*Prevalence = (2 + 1) / 203 = 0.0148 or 1.48%
The individual's pre-test probability was more than twice the onethat of the population sample, although the individual's post-test probability was less than twice the onethat of the population sample (which is estimated by the positive predictive value of the test of 10%), opposite to what would result by a less accurate method of simply multiplying relative risks.
