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Policy Simulator

What happens when you screen a population year after year? Watch the outcomes accumulate — and notice how PPV stays stuck below the coin-flip line.

Screening Parameters

10,000
1 in 10,000 (0.01%)
80%
95%
5 years Year 0

Cumulative Screening Outcomes

False Positives
True Positives
False Negatives
Positive Predictive Value (PPV) —%
50% — coin flip
0% (all false) 100% (all true)
0
False Positives
(wrongly flagged)
0
True Positives
(correctly caught)
0
False Negatives
(missed)
—:1
FP per TP
(harm per catch)

Adjust parameters and click Animate to see how screening outcomes accumulate over time.