Proportion.diagnostic.test: This function provides proportion estimates based on the...

In RajeswaranV/vcdPlus: Summary and inference of categorical data and contingency tables

Description

This function provides proportion estimates based on the given 2 x 2 table. This is an array of estimates other than association measures such as odds ratio, relative risk and risk difference. Main aim is to have efficiency of diagonstic test for a disease. Data is available in a 2 x 2 table which classifies the cases of correct / incorrect diagonsis of a test.

Usage

Proportion.diagnostic.test(ai, bi, ci, di, p)

Arguments

ai	- Numeric value representing True Positives
bi	- Numeric value representing False Positives
ci	- Numeric value representing False Negatives
di	- Numeric value representing True Negatives
p	- Numeric value representing prevelance

Details

The function takes True Positives, False Positives , False Negatives , True Negatives and prevalance as input and then calculates the efficiency of diagonstic test.

Value

A dataframe with

Sensitivity	The proportion of positives that are correctly identified as such
Specificity	The proportion of negatives that are correctly identified as such
JIndex	Sensitivity + Specificty -1
Posivitve.Predictive.Value	Proportions of positive results that are true positive
Negetive.Predictive.Value	Proportions of negative results that are true negative
Positive.likelihood.ratio	Likelihood ratio for positive results
Negative.likelihood.ratio	Likelihood ratio for negetive results
PPV.adjusted.for.Prevalance	Posivitve predictive value adjusted for prevelance
NPV.adjusted.for.Prevalance	Negetive predictive value adjusted for prevelance

References

[1] Mercaldo, N. D., Lau, K. F., & Zhou, X. H. (2007). Confidence intervals for predictive values with an emphasis to case-control studies. Statistics in medicine, 26(10), 2170-2183. [2] Upton, G. J. (2016). Categorical Data Analysis by Example. John Wiley & Sons.

See Also

Other Test methods: Partition.table, exact2x2tests.hypergeom, exact2x2tests.regular

Examples

## Example taken from Breast cancer data [reference 1]
ai=31; bi=12; ci=3; di=32; p=0.07
Proportion.diagnostic.test(ai,bi,ci,di,p)
########Interval estimation

RajeswaranV/vcdPlus documentation built on May 27, 2019, 7:28 a.m.