```
#In this example, 4 plots are drawn on one page, one plot for each
#combination of noncompliance percentage. Within a plot, the
#5-year mortality % in the control group is on the x-axis, and
#separate curves are drawn for several % reductions in mortality
#with the intervention. The accrual period is 1.5y, with all
#patients followed at least 5y and some 6.5y.
par(mfrow=c(2,2),oma=c(3,0,3,0))
morts <- seq(10,25,length=50)
red <- c(10,15,20,25)
for(noncomp in c(0,10,15,-1)) {
if(noncomp>=0) nc.i <- nc.c <- noncomp else {nc.i <- 25; nc.c <- 15}
z <- paste("Drop-in ",nc.c,"%, Non-adherence ",nc.i,"%",sep="")
plot(0,0,xlim=range(morts),ylim=c(0,1),
xlab="5-year Mortality in Control Patients (%)",
ylab="Power",type="n")
title(z)
cat(z,"\n")
lty <- 0
for(r in red) {
lty <- lty+1
power <- morts
i <- 0
for(m in morts) {
i <- i+1
power[i] <- cpower(5, 14000, m/100, r, 1.5, 5, nc.c, nc.i, pr=FALSE)
}
lines(morts, power, lty=lty)
}
if(noncomp==0)legend(18,.55,rev(paste(red,"% reduction",sep="")),
lty=4:1,bty="n")
}
mtitle("Power vs Non-Adherence for Main Comparison",
ll="alpha=.05, 2-tailed, Total N=14000",cex.l=.8)
#
# Point sample size requirement vs. mortality reduction
# Root finder (uniroot()) assumes needed sample size is between
# 1000 and 40000
#
nc.i <- 25; nc.c <- 15; mort <- .18
red <- seq(10,25,by=.25)
samsiz <- red
i <- 0
for(r in red) {
i <- i+1
samsiz[i] <- uniroot(function(x) cpower(5, x, mort, r, 1.5, 5,
nc.c, nc.i, pr=FALSE) - .8,
c(1000,40000))$root
}
samsiz <- samsiz/1000
par(mfrow=c(1,1))
plot(red, samsiz, xlab='% Reduction in 5-Year Mortality',
ylab='Total Sample Size (Thousands)', type='n')
lines(red, samsiz, lwd=2)
title('Sample Size for Power=0.80\nDrop-in 15%, Non-adherence 25%')
title(sub='alpha=0.05, 2-tailed', adj=0)
```

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