NNTintervalsRetrospective {NNTbiomarker}R Documentation

NNTintervalsRetrospective

Description

Bayes predictive intervals for sensitivity, specificity, NNTpos and NNTneg in a case-control retrospective study.

Usage

NNTintervalsRetrospective(Ncases = 10, Ncontrols = 30, NposCases = 6,
  NposControls = 2, prev = 0.15, alpha = 0.025, prior = c(1/2, 1/2))

Arguments

Ncases

Number of cases in the study

Ncontrols

Number of controls in the study

NposCases

Number of cases with positive test

NposControls

Number of controls with positive test

prev

Prevalence of the BestToTreat (versus BestToWait)

alpha

Significance level for interval.

prior

Beta parameters for prior. Default is the Jeffreys prior = c(1/2,1/2). Jaynes prior = c(0,0) won't work when #fp=1.

Value

A list with 3 components containing intervals (predictive or otherwise), with names intervalsForSN, intervalsForSP, intervalsForNNT. The intervals derive from assuming independent Jeffreys priors for SN and SP, sampling from joint independent posteriors for SN and SP incorporating the anticipated results, and applying NNT.from.sesp (Bayes theorem) to each sampled pair to obtain a sample of NNTpos and NNTneg.


[Package NNTbiomarker version 0.29.11 Index]