miceData: Lung Tumor Interval Censored Data from Hoel and Walburg 1972

Description Fields References Examples

Description

RFM mice were sacrificed and examined for lung tumors. This resulted in current status interval censored data: if the tumor was present, this implied left censoring and if no tumor was present this implied right censoring. Mice were placed in two different groups: conventional environment or germ free environment.

Fields

l

left side of observation interval

u

right side of observation interval

grp

Group for mouse. Either ce (conventional environment) or ge (grem-free environment)

References

Hoel D. and Walburg, H.,(1972), Statistical analysis of survival experiments, The Annals of Statistics, 18, 1259-1294

Examples

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data(miceData)
 
coxph_fit <- ic_sp(Surv(l, u, type = 'interval2') ~ grp, 
                    bs_samples = 50,	
                    data = miceData)
 
#In practice, more bootstrap samples should be used for inference
#Keeping it quick for CRAN testing purposes 
 
summary(coxph_fit)

Example output

Loading required package: survival
Loading required package: Rcpp
Loading required package: coda

Model:  Cox PH
Baseline:  semi-parametric 
Call: ic_sp(formula = Surv(l, u, type = "interval2") ~ grp, data = miceData, 
    bs_samples = 50)

      Estimate Exp(Est) Std.Error z-value       p
grpge   0.6785    1.971    0.3219   2.108 0.03505

final llk =  -76.56894 
Iterations =  54 
Bootstrap Samples =  50 
WARNING: only  50  bootstrap samples used for standard errors. 
Suggest using more bootstrap samples for inference

icenReg documentation built on Oct. 16, 2018, 1:04 a.m.