ahr_blinded.RdBased on blinded data and assumed hazard ratios in different intervals, compute a blinded estimate of average hazard ratio (AHR) and corresponding estimate of statistical information. This function is intended for use in computing futility bounds based on spending assuming the input hazard ratio (hr) values for intervals specified here.
ahr_blinded( Srv = Surv(time = simtrial::Ex1delayedEffect$month, event = simtrial::Ex1delayedEffect$evntd), intervals = array(3, 3), hr = c(1, 0.6), ratio = 1 )
| Srv | input survival object (see |
|---|---|
| intervals | Vector containing positive values indicating interval lengths where the exponential rates are assumed. Note that a final infinite interval is added if any events occur after the final interval specified. |
| hr | vector of hazard ratios assumed for each interval |
| ratio | ratio of experimental to control randomization. |
A tibble with one row containing
`AHR` blinded average hazard ratio based on assumed period-specific hazard ratios input in `failRates`
and observed events in the corresponding intervals
`Events` total observed number of events, `info` statistical information based on Schoenfeld approximation,
and info0 (information under related null hypothesis) for each value of `totalDuration` input;
if `simple=FALSE`, `Stratum` and `t` (beginning of each constant HR period) are also returned
and `HR` is returned instead of `AHR`
library(simtrial) library(survival) ahr_blinded(Srv = Surv(time = simtrial::Ex2delayedEffect$month, event = simtrial::Ex2delayedEffect$evntd), intervals = c(4,100), hr = c(1, .55), ratio = 1)#> # A tibble: 1 x 4 #> Events AHR theta info0 #> <dbl> <dbl> <dbl> <dbl> #> 1 228 0.826 -0.191 57