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StatisticsClinical bridge

Number Needed to Screen Calculator

Other languages 日本語 | English

Convert screening detection yield into number needed to screen, then review prevalence, detection rate, and yield together on one page.

How to use

  1. Choose whether you want to enter prevalence and detection rate or a direct detection yield.
  2. Enter percentages and decimal places, then calculate.
  3. Read detection yield first, then NNS.

Wave 13 clinical bridge

Detection yield → NNS

The share URL stores only mode and decimal settings.

Choose either prevalence × detection rate or a direct detection yield to estimate number needed to screen.

Where this fits

Use this page when you want a people-needed interpretation for screening yield. NNH and ARR / NNT translate absolute risk gaps into people-needed language, while post-test odds focuses on belief updating after a result.

FAQ

What does this page calculate?

It converts a screening detection yield into number needed to screen and optionally derives that yield from prevalence and detection rate.

What is number needed to screen?

It is the number of people who need to be screened to detect one target case under the assumptions you entered.

Can I enter a direct yield?

Yes. Switch to direct yield mode when you already know the absolute detection yield per screened person.

Does the share URL include my rates?

No. The share URL stores only light settings such as mode and decimal places. Numeric inputs stay in your browser.