R: Converts between etm and msdata format

etm2msdata {mstate} | R Documentation

## Converts between etm and msdata format

### Description

Converts multi-state data back and forth between etm and msdata formats. Covariates have to be dealt with separately.

### Usage

    etm2msdata(etmdata, id, tra, covs)

### Arguments

`etmdata` | Multi-state data in `etm` format
`id` | Column name identifying the subject id
`tra` | Transition matrix in `etm` format
`covs` | Vector of column names containing covariates to be included

### Details

`msdata2etm` will convert from `msdata` format to `etm` format; `etm2msdata` will convert from `etm` format to `msdata` format. Both `msdata2etm` and `etm2msdata` work with basic time-fixed covariates. Time-dependent covariates are not supported. The function `msdata2etm` will work for transition-specific covariates, but the result does not really make much sense when used in etm.

### Author(s)

Hein Putter H.Putter@lumc.nl

### Examples

    # Transition matrix for illness-death model
    tmat <- trans.illdeath()
    # Data in wide format, for transition 1 this is dataset E1 of
    # Therneau & Grambsch (T&G)
    tg <- data.frame(id=1:6,illt=c(1,1,6,6,8,9),ills=c(1,0,1,1,0,1),
                     dt=c(5,1,9,7,8,12),ds=c(1,1,1,1,1,1),
                     x1=c(1,1,1,0,0,0),x2=c(6:1))
    # Data in long format using msprep
    tglong <- msprep(time=c(NA,"illt","dt"),status=c(NA,"ills","ds"),
                     data=tg,keep=c("x1","x2"),trans=tmat, id="id")
    # Same thing in etm format
    tra <- trans2tra(tmat)
    tgetm <- msdata2etm(tglong, id="id")
    tgetm <- msdata2etm(tglong, id="id", covs=c("x1", "x2")) # with covariates
    # And back
    etm2msdata(tgetm, id="id", tra=tra)
    etm2msdata(tgetm, id="id", tra=tra, covs=c("x1", "x2")) # with covariates

[Package mstate version 0.3.2 Index]