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

 surv.land.obs R Documentation

## Estimates survival using landmark estimation

### Description

Estimates the probability of survival past some specified time using landmark estimation for an observational study setting

### Usage

surv.land.obs(tl, dl, tt, landmark, short = NULL, z.cov = NULL, var = FALSE,
conf.int = FALSE, ps.weights, weight.perturb = NULL, perturb.ps = FALSE,
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.obs 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. & Griffin B.A. (2017). Landmark Estimation of Survival and Treatment Effects in Observational Studies. Lifetime Data Analysis, 23:161-182.

### Examples

data(example_obs)
W.weight = ps.wgt.fun(treat = example_obs$treat, cov.for.ps = as.matrix(example_obs$Z))
example_obs.treat = example_obs[example_obs$treat == 1,] #executable but takes time #surv.land.obs(tl=example_obs.treat$TL, dl = example_obs.treat$DL, tt=2, landmark = 1, #short = cbind(example_obs.treat$TS,example_obs.treat$DS), z.cov = example_obs.treat$Z,
#ps.weights = W.weight[example_obs\$treat == 1])


landest documentation built on Aug. 26, 2023, 1:08 a.m.