Pre- and post-test probability: Difference between revisions

Revision as of 04:00, 26 February 2023

Revision as of 12:48, 7 April 2023

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The post-test probability of disease given a negative result is calculated as:

Negative posttest probability = 1 - (False negatives / (False negatives + True negatives))

The validity of the equations above also depend on that the sample from the population does not have substantial [[sampling bias]] that make the groups of those who have the condition and those who do not substantially disproportionate from corresponding prevalence and "non-prevalence" in the population. In effect, the equations above are not valid with merely a [[case-control study]] that separately collects one group with the condition and one group without it.