ypsummary: The main function of the package provides five summary...

Description Usage Arguments Details Value References Examples

View source: R/ypsummary.R

Description

The main function of the package provides five summary measures below:

Usage

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## Default S3 method:
ypsummary(time, event, group, tau, alpha = 0.05,
  tie = TRUE, bound = 50, repnum = 2000, ...)

Arguments

...

for S4 method only.

time

the numeric vector of observations pooled from the two groups

event

the numeric vector of the right-censoring indicator (event = 1, censored = 0)

group

the numeric vector of the group indicator (treatment = 1, control = 0)

tau

the upper end of the range used in defining the summary measures. Must be user-specified.

alpha

the significance level. The default value is 0.05.

tie

if it is TRUE, very tiny values will be added to the observations when sorting them.

bound

the boundary (-bound, bound) for estimating the parameters relevant to a short-term and a long-term hazard ratio in Yang and Prentice model (Yang and Prentice, 2005). These parameters are β_1 and β_2 in their notations. The default boundary is (-50, 50).

repnum

the number of replications for the resampling method in obtaining the limiting variance estimators of the measures. The default value is 2000.

Details

The hazard ratio hr(x) is defined as the ratio of λ_t(x) over λ_c(x) which are the treatment and control hazard functions, respectively.

Value

Estimate

The point estimate for the corresponding summary meausure

CI

The confidence interval constructed by a re-sampling method. If the measure is a ratio, the z-value is the standardized log of the estimate. If the measure is a difference, the z-value is the standardized estimate.

z-value

normally distributed value derived from the asymptotic results

p-value

the (two-sided) p-value using z-value

References

Yang, S (2017). Improving testing and description of treatment effect in clinical trials with survival outcomes. Pre-print.

Yang S, and Ross L. Prentice (2005). Semiparametric analysis of short-term and long-term hazard ratios with two-sample survival data. Biometrika, 92.1:1-17.

Examples

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library(ClinicalTrialSummary)
data(ggas)
result <- ypsummary(time=ggas$time, event=ggas$event, group=ggas$group, tau=8.2)
result

ClinicalTrialSummary documentation built on Nov. 17, 2017, 4:01 a.m.