ComparisonSurv (version 1.1.1)

Fixpoint.test: Statistical inference methods for testing at a fixed time point

Description

A function used to produce the results of various statistical inference methods for testing at a fixed time point.

Usage

Fixpoint.test(time, status, group, t0)

Value

A list containing the following components:

est.g0

The estimation of survival rates at the fixed timepoint for control group.

est.g1

The estimation of survival rates at the fixed timepoint for treatment group.

test

The results of statistical inference at the fixed timepoint.

method

Containing 5 types of statistical inference methods: naive, log, cloglog, arcsin, and logist. See more details in references.

t0

The prespecified fixed time point.

est

The survival rate at the prespecified timepoint.

lower.95.CI

The lower 95 percent pointwise confidence interval for the survival function.

upper.95.CI

The upper 95 percent pointwise confidence interval for the survival function.

statistic

The statistics of corresponding methods.

pvalue

The test P value of corresponding methods.

Arguments

time

The follow up time for right censored data.

status

The status indicator, normally 1=event, 0=alive or right censored.

group

The group indicator for comparison, and the elements of this vector must take either 0 or 1. Normally, 0= control group, 1= treatment group.

t0

The fixed time point for testing.

References

[1]Klein JP, Logan B, Harhoff M, et al. Analyzing survival curves at a fixed point in time. Statistics in Medicine, 2007, 26(24):4505-4519.

[2]Anderson JR, Pike LBC. Approximate Confidence Intervals for Probabilities of Survival and Quantiles in Life-Table Analysis. Biometrics, 1982, 38(2):407-416.

Examples

#get 'Crossdata' from package
data(Crossdata)
data1<-Crossdata
#
#if there exist differences at 6 months and 12 months
Fixpoint.test(data1$time,data1$status,data1$group,t0=0.5)
Fixpoint.test(data1$time,data1$status,data1$group,t0=1)