DTAT (version 0.3-7)

dose.survfit: Calculate a dose-survival curve from a dose titration study, adding a confidence band

Description

The 'dose-survival curve' is nothing other than an empirical cumulative distribution for MTDi in the sampled population. The term 'survival' is suggested in part by our application of the Kaplan-Meier estimator to interval-censored toxicity information.

Usage

dose.survfit(de, method = "rothman", avoid.degeneracy = TRUE, conf.level = 0.8)

Value

An object of class survfit.

Arguments

de

A dose titration experiment like the data slot of class DE

method

The method to be used by km.ci when calculating CI

avoid.degeneracy

When TRUE, this parameter directs the function to introduce artificial events into the dose titration experiment, to avoid degeneracies at the lower and upper ends of the dose-survival curve.

conf.level

Confidence level for KM confidence band.

Author

David C. Norris

Details

TODO: Describe details of degeneracy avoidance, once these have stabilized.

See Also

dose.survival, km.ci

Examples

CV <- 0.7; mean_mtd <- 1.0
shape <- CV^-2; scale <- mean_mtd/shape
trial <- new("DE", doses=0.25 * 1.4^(0:6),
             MTDi=rgamma(24, shape=shape, scale=scale),
             units="mg")
trial <- titration(trial, periods=10)
sf <- dose.survfit(trial@data)
summary(sf)