NNT.to.pv

pv.from.NNT

NNT for a patient with positive test result

NNTpos

NNT for a patient with negative test result

NNTneg

A matrix or vector of (NNTpos, NNTneg) values.

Prevalence of the "BestToTreat" group before testing.

calculate.se.sp


Convert between (NNTpos, NNTneg)  and (PPV, NPV).


Helps a clinical trial team  discuss
the clinical goals  of a well-defined biomarker with a diagnostic,
staging, prognostic, or predictive purpose.  From this discussion will
come a statistical plan for a (non-randomized) validation trial.
Both prospective and retrospective trials are supported. In a specific
focused discussion, investigators should determine the range of
"discomfort" for the NNT, number needed to treat.  The meaning of
the discomfort range, [NNTlower, NNTupper], is that within this range
most physicians would feel discomfort either in treating or withholding
treatment. A pair of NNT values bracketing that range, NNTpos and NNTneg,
become the targets of the study's design.  If the trial can demonstrate
that a positive biomarker test yields an NNT less than NNTlower,
and that a negative biomarker test yields an NNT less than NNTlower,
then the biomarker may be useful for patients. A highlight of the package
is visualization of a "contra-Bayes" theorem, which produces criteria for
retrospective case-controls studies.

NNT.to.pv: NNT.to.pv

Description

Usage

Arguments

Value