R: Make a cross-section of multi-state data at a given time...

xsect {mstate} | R Documentation

## Make a cross-section of multi-state data at a given time point

### Description

Given a dataset in long format, for instance generated by `msprep`, this function takes a cross-section at a given time point, to list the subjects under observation (at risk) at that time point and the states currently occupied.

### Usage

    xsect(msdata, xtime = 0)

### Arguments

`msdata` | An object of class `"msdata"`, such as output by `msprep`
`xtime` | The time point at which the intersection is to be made

### Details

It is possible that subjects have moved to one of the absorbing states prior to `xtime`; this is NOT taken into account. The function `xsect` only concerns subjects currently (at `time`) at risk.

### Value

A list containing `idstate`, a data frame containing `id`'s and `state`, the number of the state currently occupied; `atrisk`, the number at risk, and `prop`, a table counting how many of those at risk occupy which state.

### Author(s)

Hein Putter H.Putter@lumc.nl

### Examples

    tmat <- trans.illdeath(names=c("Tx","PR","RelDeath"))
    data(ebmt3) # data from Section 4 of Putter, Fiocco & Geskus (2007)
    msebmt <- msprep(time=c(NA,"prtime","rfstime"),status=c(NA,"prstat","rfsstat"),
    		data=ebmt3,trans=tmat)
    # At the start everyone is in state 1 (default xtime=0 is used)
    xsect(msebmt)
    # At 5 years
    xsect(msebmt, xtime=1826)

[Package mstate version 0.3.1 Index]