ypsummary: The main function of the package provides five summary... In ClinicalTrialSummary: Summary Measures for Clinical Trials with Survival Outcomes

Description

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

• The average hazard ratio (AHR): ∫ _{0}^{τ} hr(x)dx

• The weighted average hazard ratio (WAHR): ∫ _{0}^{τ} hr(x)dw(x) where dw(x) = dF_c(x)/F_c(τ)

• The restricted superiority probability ratio (RSPR): ∫ _{0}^{τ} S_c(x)dF_t(x) / ∫ _{0}^{τ} S_t(x)dF_c(x)

• The restricted mean survival difference (RMSD): ∫ _{0}^{τ} S_t(x)dx - ∫ _{0}^{τ} S_c(x)dx

• The ratio of restricted mean times lost (RMSR): (τ - ∫ _{0}^{τ} S_t(x)dx) / (τ - ∫ _{0}^{τ} S_c(x)dx)

Usage

 ```1 2 3``` ```## 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

 ```1 2 3 4``` ```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.