# surv.land.rct: Estimates survival using landmark estimation In landest: Landmark Estimation of Survival and Treatment Effect

## Description

Estimates the probability of survival past some specified time using landmark estimation for a randomized trial setting

## Usage

 1 2 surv.land.rct(tl, dl, tt, landmark, short = NULL, z.cov = NULL, var = FALSE, conf.int = FALSE, weight.perturb = NULL, perturb.vector = FALSE, bw = NULL) 

## Arguments

 tl observed event time of primary outcome, equal to min(T, C) where T is the event time and C is the censoring time. dl event indicator, equal to I(T

## Details

See documentation for delta.land.rct for details.

## Value

A list is returned:

 S.estimate the estimate of survival at the time of interest, \hat{S}(t) = P(T>t) S.var  the variance estimate of \hat{S}(t); if var = TRUE or conf.int = TRUE conf.int.normal.S a vector of size 2; the 95% confidence interval for \hat{S}(t) based on a normal approximation; if conf.int = TRUE conf.int.quantile.S a vector of size 2; the 95% confidence interval for \hat{S}(t) based on sample quantiles of the perturbed values, described above; if conf.int = TRUE perturb.vector a vector of size x where x is the number of columns of the provided weight.perturb matrix (or x=500 if weight.perturb is not provided); the perturbed values of \hat{S}(t); if perturb.vector = TRUE and either var=TRUE or conf.int = TRUE

Layla Parast

## References

Parast, L., Tian, L., & Cai, T. (2014). Landmark Estimation of Survival and Treatment Effect in a Randomized Clinical Trial. Journal of the American Statistical Association, 109(505), 384-394.

## Examples

 1 2 3 4 5 data(example_rct) example_rct.treat = example_rct[example_rct$treat == 1,] #executable but takes time #surv.land.rct(tl=example_rct.treat$TL, dl = example_rct.treat$DL, tt=2, landmark = 1, #short = cbind(example_rct.treat$TS,example_rct.treat$DS), z.cov = example_rct.treat$Z) 

landest documentation built on Nov. 16, 2021, 9:24 a.m.