# data.sim.ibm:
A simulated data set under a mixed model with random intercept, integrated Brownian motion and
multivariate normal response distribution

### Description

A longitudinal data set containing measurements on 500 subjects, each with their own sequence of follow-up time points
collected at irregularly spaced follow-up time points.

### Usage

### Format

A data frame with 8462 observations on the following 6 variables.

`id`

a numeric vector: subject identification

`sex`

a numeric vector: 0 = male, 1 = female

`bage`

a numeric vector: baseline age in years

`fu`

a numeric vector: follow-up time in years

`pwl`

a numeric vector: piecewise linear term,
calculated as, max(0, age-56.5)

`log.egfr`

a numeric vector: response variable representing
natural logarithm of estimated glomerular filtration rate

### Details

For the details of the true parameter settings, see Diggle, Sousa and Asar (2015).

### References

Diggle PJ, Sousa I, Asar O (2015) Real time monitoring of progression towards renal failure in primary care patients.
*Biostatistics*, 16(3), 522-536.

### Examples