ntpp.easy_tool: An S3 Method to Compute the Ratio of Total Tests to Positive...

In sgutreuter/screenr: Construction of Binary Test-Screening Rules

An S3 Method to Compute the Ratio of Total Tests to Positive Results

Description

ntpp.easy_tool computes the ratio of the total number of tests performed per positive test result and the anticipated fraction of the untested (those screened out of testing) who would actually test positive.

Usage

## S3 method for class 'easy_tool'
ntpp(object, ..., prev = NULL)

Arguments

object	an easy_tool-class object produced by easy_tool.
...	optional arguments to ntpp methods.
prev	an optional positive proportion for the test outcome; if missing the test positivity is obtained from object.

Details

The anticipated number of tests required to detect a single positive nntp is given by

nntp = (SeP + (1 - Sp)(1 - P)) / SeP

where Se is sensitivity, P is prevalence and Sp is specificity. The anticipated positivity among those screened out is given by

Puntested = ((1 - Se)P) / ((1 - Se)P + Sp (1 - P))

Value

ntpp.easy_tool returns a dataframe containing the following columns:

sensitivity

The sensitivity (proportion) of the screener.

specificity

The specificity (proportion) of the screener.

ntpp

the number of tests required to discover a single positive test result.

prev_untested

The antipated proportion who would positive among those who are screened out of testing.

Examples

attach(uniobj1)
tool <- easy_tool(uniobj1, max = 3, crossval = TRUE)
ntpp(tool)

sgutreuter/screenr documentation built on Nov. 20, 2022, 2:41 a.m.