Residual Carrier Risk After a Negative Carrier Screen
Residual carrier risk after a negative screen, by Bayes' theorem from the carrier frequency and the test's detection rate.
Open the calculator → Runs in your browser. Data leaves only if you deliberately send a problem report from the interactive tool.
Example
- Prior carrier frequency
- 1/58
- Detection rate of the test in that population
- 91%
Result: Residual carrier risk after a negative screen: 1 in 634
The tool opens with these values already filled in. Replace them with your own.
What you enter
- Prior carrier frequency (from the report)
- Detection rate of the test in that population
How this is calculated
Citation
Stated arithmetic: Bayes' theorem, the prior carrier frequency times the chance a carrier tests negative (1 minus the detection rate), over that plus the non-carrier probability. Both inputs are entered from the report.
A reference and educational tool. Not medical, legal, or financial advice, and not a substitute for clinician judgment.