interval_posterior_nominator {bpp}

Posterior density conditional on interim result, only known as interval, is proportional to the value of this function

Description

If we update the prior with the knowledge that the interim estimate was between a futility and efficacy boundary at an interim analysis, we get a density that is proportional to the value of this function.

Usage

interval_posterior_nominator(x, prior = c("normal", "flat"), 
          IntEffBoundary, IntFutBoundary, interimSE, priormean, ...)

Arguments

x

Value at which to evaluate the function.

prior

Prior density on effect sizes.

IntEffBoundary

Efficacy boundary at the interim analysis.

IntFutBoundary

Futility boundary at the interim analysis.

interimSE

(Known) standard error of interimmean, i.e. at interim analysis.

priormean

Prior mean.

...

Further arguments specific to the chosen prior (see bpp for examples).

Value

Value of the function, a real number.

Author(s)

Kaspar Rufibach (maintainer)
[e-mail]

References

Rufibach, K., Jordan, P., Abt, M. (2016a). Sequentially Updating the Likelihood of Success of a Phase 3 Pivotal Time-to-Event Trial based on Interim Analyses or External Information. J. Biopharm. Stat., 26(2), 191–201.

Examples

# type ?bpp_1interim for code of all the computations in Rufibach et al (2016a).