tad {nonmemica}

Calculate Time Since Most Recent Dose

Description

Calculate time since most recent dose. Considers ADDL, but may not work with simultaneous dose records.

Usage

tad(
  x,
  dose = rep(FALSE, length(x)),
  addl = rep(0, length(x)),
  ii = rep(0, length(x)),
  index = rep(1, length(x)),
  pre = TRUE,
  ...
)

Arguments

x

a numeric vector of event times

dose

length x logical indicating which of x are dose times

addl

length x integer: number of additional doses

ii

length x numeric: interdose interval for addl

index

length x factor (optional) indicating subgroups to evaluate

pre

assume that simultaneous sample precedes implied dose

...

passed to tod()

Value

numeric

See Also

tod

Other tad: tod()

Examples

data(tad1)
x <- tad1
head(x)
x$tad <- tad(
   x = x$TIME,
   dose = x$EVID %in% c(1,4) & is.na(x$C),
   addl = x$ADDL,
   ii = x$II,
   index = x$ID
 )
head(x)