Package 'Tariff'

Title: Replicate Tariff Method for Verbal Autopsy
Description: Implement the Tariff algorithm for coding cause-of-death from verbal autopsies. The Tariff method was originally proposed in James et al (2011) <DOI:10.1186/1478-7954-9-31> and later refined as Tariff 2.0 in Serina, et al. (2015) <DOI:10.1186/s12916-015-0527-9>. Note that this package was not developed by authors affiliated with the Institute for Health Metrics and Evaluation and thus unintentional discrepancies may exist between the this implementation and the implementation available from IHME.
Authors: Zehang Li, Tyler McCormick, Sam Clark
Maintainer: Zehang Li <[email protected]>
License: GPL-2
Version: 1.0.5
Built: 2024-10-06 06:47:38 UTC
Source: CRAN

Help Index


Plot CSMF of the results obtained from Tariff algorithm

Description

This function plots the CSMF of the fitted results.

Usage

## S3 method for class 'tariff'
plot(x, top = NULL, min.prob = 0, ...)

Arguments

x

fitted object from tariff

top

maximum causes to plot

min.prob

minimum fraction for the causes plotted

...

Arguments to be passed to/from graphic function

Examples

data("RandomVA3")
test <- RandomVA3[1:200, ]
train <- RandomVA3[201:400, ]
allcauses <- unique(train$cause)
fit <- tariff(causes.train = "cause", symps.train = train, 
				symps.test = test, causes.table = allcauses)
plot(fit, top = 10, main = "Top 5 population COD distribution")
plot(fit, min.prob = 0.05, main = "Ppulation COD distribution (at least 5%)")

Print method for the summary of the results obtained from Tariff algorithm

Description

This function prints the summary message of the fitted results.

Usage

## S3 method for class 'tariff_summary'
print(x, ...)

Arguments

x

summary object for Tariff fit

...

not used


400 records of Sample Input

Description

This is a dataset consisting of 400 arbitrary sample input deaths randomly sampled from cleaned PHMRC data.

Format

400 arbitrary input records.

Examples

data(RandomVA3)
head(RandomVA3$train)
head(RandomVA3$test)

Grouping of causes in RandomVA3

Description

This is a matrix specifying a default grouping of the causes used in RandomVA3.

Format

17 by 2 matrix

Examples

data(SampleCategory3)
SampleCategory3

Summary of the results obtained from Tariff algorithm

Description

This function prints the summary message of the fitted results.

Usage

## S3 method for class 'tariff'
summary(object, top = 5, id = NULL, ...)

Arguments

object

fitted object from tariff

top

number of top CSMF to show

id

the ID of a specific death to show

...

not used

Examples

data("RandomVA3")
test <- RandomVA3[1:200, ]
train <- RandomVA3[201:400, ]
allcauses <- unique(train$cause)
fit <- tariff(causes.train = "cause", symps.train = train, 
			symps.test = test, causes.table = allcauses)
correct <- which(fit$causes.test[,2] == test$cause)
accuracy <- length(correct) / dim(test)[1]
summary(fit)
summary(fit, top = 10)
summary(fit, id = "p849", top = 3)

Replicate Tariff methods

Description

This function implements Tariff method.

Usage

tariff(causes.train, symps.train, symps.test, causes.table = NULL,
  use.rank = TRUE, nboot.rank = 1, use.sig = TRUE, nboot.sig = 500,
  use.top = FALSE, ntop = 40, ...)

Arguments

causes.train

character vector of causes, or the column name of cause in the training data

symps.train

N.train by S matrix

symps.test

N.test by S matrix

causes.table

list of causes in the data

use.rank

logical indicator for whether using ranks instead of scores

nboot.rank

number of re-sampling for baseline rank comparison. Default to 1, which resamples training data to have a uniform cause distribution of the same size. Set this to 0 removes bootstrapping the training dataset.

use.sig

logical indicator for whether using significant Tariff only

nboot.sig

number of re-sampling for testing significance.

use.top

logical indicator for whether the tariff matrix should be cleaned to have only top symptoms

ntop

number of top tariff kept for each cause

...

not used

Value

score

matrix of score for each cause within each death

causes.train

vector of most likely causes in training data

causes.test

vector of most likely causes in testing data

csmf

vector of CSMF

causes.table

cause list used for output, i.e., list of existing causes in the training data

use.rank

logical indicator for whether using ranks instead of scores

Author(s)

Zehang Li, Tyler McCormick, Sam Clark

Maintainer: Zehang Li <[email protected]>

References

James, S. L., Flaxman, A. D., Murray, C. J., & Population Health Metrics Research Consortium. (2011). Performance of the Tariff Method: validation of a simple additive algorithm for analysis of verbal autopsies. Population Health Metrics, 9(1), 1-16.

Serina, P., Riley, I., Stewart, A., James, S. L., Flaxman, A. D., Lozano, R., ... & Ahuja, R. (2015). Improving performance of the Tariff Method for assigning causes of death to verbal autopsies. BMC medicine, 13(1), 1.

Tyler H. McCormick, Zehang R. Li, Clara Calvert, Amelia C. Crampin, Kathleen Kahn and Samuel J. Clark(2016) Probabilistic cause-of-death assignment using verbal autopsies, http://arxiv.org/abs/1411.3042 To appear, Journal of the American Statistical Association

Examples

data("RandomVA3")
test <- RandomVA3[1:200, ]
train <- RandomVA3[201:400, ]
allcauses <- unique(train$cause)
fit <- tariff(causes.train = "cause", symps.train = train, 
				symps.test = test, causes.table = allcauses)
correct <- which(fit$causes.test[,2] == test$cause)
accuracy <- length(correct) / dim(test)[1]