Work out screening yield instantly with clear inputs, formula shown and shareable results.
Divides cases detected by people screened to give the screening yield, and inverts it to give the number needed to screen.
Screening yield
Yield (%) = cases detected / people screened x 100; number needed to screen = people screened / cases detected
Underlying prevalence in the group screened, plus test sensitivity; targeting higher-risk groups raises yield.
It indicates efficient targeting, but overdiagnosis means some detected cases would never have caused harm.