delta.t.surv.estimate function

Calculates robust residual treatment effect accounting only for primary outcome information up to a specified time

This function calculates the robust estimate of the residual treatment effect accounting only for primary outcome information up to $t_0$ i.e. the hypothetical treatment effect if survival up to $t_0$ in the treatment group looks like survival up to $t_0$ in the control group. Ideally this function is only used as a helper function and is not directly called.

delta.t.surv.estimate(xone, xzero, deltaone, deltazero, t, weight.perturb = NULL,
landmark, approx = T)

Arguments

• xone: numeric vector, the observed event times in the treatment group, X = min(T,C) where T is the time of the primary outcome and C is the censoring time.
• xzero: numeric vector, the observed event times in the control group, X = min(T,C) where T is the time of the primary outcome and C is the censoring time.
• deltaone: numeric vector, the event indicators for the treatment group, D = I(T<C) where T is the time of the primary outcome and C is the censoring time.
• deltazero: numeric vector, the event indicators for the control group, D = I(T<C) where T is the time of the primary outcome and C is the censoring time.
• t: the time of interest.
• weight.perturb: weights used for perturbation resampling.
• landmark: the landmark time $t_0$ or time of surrogate marker measurement.
• approx: TRUE or FALSE indicating whether an approximation should be used when calculating the probability of censoring; most relevant in settings where the survival time of interest for the primary outcome is greater than the last observed event but before the last censored case, default is TRUE.

Details

Details are included in the documentation for R.t.surv.estimate.

References

Parast, L., Cai, T., & Tian, L. (2017). Evaluating surrogate marker information using censored data. Statistics in Medicine, 36(11), 1767-1782.

Returns

$\hat{\Delta}_T(t,t_0)$, the robust residual treatment effect estimate accounting only for survival up to $t_0$.

Author(s)

Layla Parast

Note

If the treatment effect is not significant, the user will receive the following message: "Warning: it looks like the treatment effect is not significant; may be difficult to interpret the residual treatment effect in this setting".

Examples

data(d_example_surv)
names(d_example_surv)