cp: Conditional power given observed log hazard ratio

In PWEALL: Design and Monitoring of Survival Trials Accounting for Complex Situations

Conditional power given observed log hazard ratio

Description

This will calculate the conditional power given the observed log hazard ratio based on Cox model

Usage

cp(Dplan=300,alpha=0.05,two.sided=1,pi1=0.5,Obsbeta=log(seq(1,0.6,by=-0.01)),
   BetaD=log(0.8),Beta0=log(1),prop=seq(0.1,0.9,by=0.1))

Arguments

Dplan	Planned number of events at study end
alpha	Type 1 error rate
two.sided	=1 two-sided test and =0 one-sided test
pi1	Allocation probability for the treatment group
Obsbeta	observed log hazard ratio
BetaD	designed log hazard ratio, i.e. under alternative hypothesis
Beta0	null log hazard ratio, i.e. under null hypothesis
prop	proportion of Dplan observed

Details

This is to calculated conditional power at time point when certain percent of target number of event has been observed and an observed log hazard ratio is provided.

Value

CPT	Conditional power under current trend
CPN	Conditional power under null hypothesis
CPD	Conditional power according to design, i.e. under alternative hypothesis

Note

This will calculate the conditional power given the observed log hazard ratio based on Cox model

Author(s)

Xiaodong Luo

References

Halperin, Lan, Ware, Johnson and DeMets (1982). Controlled Clinical Trials.

See Also

cpboundary,cpstop

Examples

###Calculate the CP at 10-90 percent of the target 300 events when the observed HR 
###are seq(1,0.6,by=-0.01) with 2:1 allocation 
###ratio between the treatment group and the control group
cp(pi1=2/3)

PWEALL documentation built on Aug. 9, 2023, 9:08 a.m.