dejaVu (version 0.3.1)

copy_reference: Create a copy reference ImputeMechanism object

Description

Missing counts for subjects in both arms are imputed by assuming the rate before and dropout are both equal to the control (reference) estimated rate. This corresponds to what is usually termed the copy reference assumption.

Usage

copy_reference(proper = TRUE)

Value

An ImputeMechanism object

Arguments

proper

If proper=TRUE then proper imputation is performed, in which each imputation is created based on parameters values drawn from the (approximate) posterior distribution of the imputation model. If proper=FALSE, improper imputation is performed. This means all imputed datasets are generated conditional on the maximum likelihood estimates of the parameters.

See Also

ImputeMechanism.object

Examples

 
sim <- SimulateComplete(study.time=365,number.subjects=50,
                        event.rates=c(0.01,0.005),dispersions=0.25)
sim.with.MCAR.dropout <- SimulateDropout(sim,
                                         drop.mechanism = ConstantRateDrop(rate = 0.0025))
fit <- Simfit(sim.with.MCAR.dropout)
imps <- Impute(fit, copy_reference(), 10)