thregI {thregI}

fit threshold regression for interval-censored data

Description

Extend right-censored data of Xiao et al. (2015) into interval-censored data. Fit a threshold regression model for interval-censored data and calculate the prediction of the initial health status value and the drift value of the health process.

Usage

thregI(formula, data)

Arguments

formula

a formula object, which has the response on the left of a ~ operator, and the explaination variables on the right. The response must be a survival object as returned by the Surv(). The | operator on the left-hand side is used for the linear regression function of ln{y_0} and right-hand side is for specifing explaination variables of \mu. A constant ln{y_0} or \mu is allowed, let 0 or 1 as a placeholder on the left or right of the | operator.

data

a data frame must contains two time points (L and R) in which to through the Surv() of R package survival by type = interval2 and interpret the variables named in the formula.

Author(s)

Man-Hua Chen

Maintainer: Man-Hua Chen < [e-mail] >

References

Xiao T, Whitmore GA, He X and Lee M-LT. (2015) The R Package threg to Implement Threshold Regression Models. Journal of Statistical Software 66, 1141-1156.

Xiao T. (2013) threg: Threshold Regression. R~package version 1.0.3, URL https://CRAN.R-project.org/package=threg.

Examples

#load the data "bcos"
data("bcos", package="thregI")

#transform the "treatment" variable into factor variable f.treatment
bcos$f.treatment=factor(bcos$treatment)

#fit the threshold regression model on the factor variable f.treatment
fit<-thregI(Surv(left, right, type='interval2')~f.treatment|f.treatment, data=bcos)
fit