dataNested: Simulated data with two levels of grouping

In frailtypack: Shared, Joint (Generalized) Frailty Models; Surrogate Endpoints

Simulated data with two levels of grouping

Description

This contains a simulated sample of 400 observations which allow establishing 20 clusters with 4 subgroups and 5 subjects in each subgroup, in order to obtain two levels of grouping. This data set is useful to illustrate how to fit a nested model. Two independent gamma frailty parameters with a variance fixed at 0.1 for the cluster effect and at 0.5 for the subcluster effect were generated. Independent survival times were generated from a simple Weibull baseline risk function. The percentage of censoring data was around 30 per cent. The right-censoring variables were generated from a uniform distribution on [1,36] and a left-truncating variable was generated with a uniform distribution on [0,10]. Observations were included only if the survival time is greater than the truncated time.

Usage

data(dataNested)

Format

This data frame contains the following columns:

group

group identification variable

subgroup

subgroup identification variable

t1

start of interval (0 or truncated time)

t2

end of interval (death or censoring time)

event

censoring status (0: alive, 1: death)

cov1

dichotomous covariate (0,1)

cov2

dichotomous covariate (0,1)

Source

V. Rondeau, L. Filleul, P. Joly (2006). Nested frailty models using maximum penalized likelihood estimation. Statistics in Medecine, 25, 4036-4052.

frailtypack documentation built on Oct. 20, 2024, 1:08 a.m.