rld (version 1.0)

calcVEk: Calculate Per-Challenge Vaccine Efficacy

Description

This function calculate the estimated per-challenge vaccine efficacy.

Usage

calcVEk(object, newdata, CIlevel=0.95)

Arguments

object

a fitted object of class inheriting from "rld".

newdata

a data list for predicting vaccine efficacy where "contrgroup" and "refgroup" list names must be included.

CIlevel

a confidence level. The default is 0.95.

Value

Details

Per-challenge vaccine efficacy is defined as the relative reduction in the risk of infection caused by vaccination at a particular challenge, conditional on non-infection before the challenge. Please refer to Kang et al.(2015) for more details about the formula.

References

Kang, C., Huang, Y., and Miller, C. (2015). A discrete-time survival model with random effects for designing and analyzing repeated low-dose challenge experiments. Biostatistics, 16(2): 295-310.

See Also

calcVEt, calcpk

Examples

data(SampleData)
augdata <- transdata(data = SampleData, ndlevel = 3, nexposure = c(10, 10, 2))
fitout <- rld(formula = survival::Surv(time, delta)~factor(dose)+trt+I(I(dose==3)*trt),
              data = augdata, frailty = TRUE)

contrgroup <- 1
refgroup <- 0
predata <- list(contrgroup, refgroup)
names(predata) <- c("contrgroup", "refgroup")
names(predata$contrgroup) <- c("trt")
names(predata$refgroup) <- c("trt")

VEkout <- calcVEk(object = fitout, newdata = predata, CIlevel = 0.95)
summary(VEkout)