The post test probability can be estimated using Bayes' Theorem. This method combines the pre-test probability (the likelihood of the condition before testing) with the sensitivity and specificity of the test. The formula is:
\[ \text{Post Test Probability} = \frac{\text{Pre Test Probability} \times \text{Sensitivity}}{(\text{Pre Test Probability} \times \text{Sensitivity}) + ((1 - \text{Pre Test Probability}) \times (1 - \text{Specificity}))} \]
