power.hr.test: Power calculation for Hazard Ratio Test

In clayford/bme: Biostatistical Methods in Epidemiology

Description

Compute the power of the Hazard Ratio Test, or determine parameters to obtain a target power.

Usage

power.hr.test(n = NULL, hr, p1, pi2, sig.level = 0.05, power = NULL,
  alternative = c("two.sided", "one.sided"), tol = .Machine$double.eps^0.25)

Arguments

n	number of subjects needed for study
hr	Hazard Ratio (ie, the "ratio worth detecting")
p1	proportion of cohort with history of exposure
pi2	probability a member of unexposed cohort will die during follow-up
sig.level	significance level (Type I error probability)
power	power of test (1 minus Type II error probability)
alternative	one- or two-sided test. Can be abbreviated.
tol	numerical tolerance used in root finding, the default providing (at least) four significant digits. Root finding refers to uniroot, which is used to find sample size given power.

Details

Exactly one of the parameters n and power must be passed as NULL, and that parameter is determined from the others.

Value

Object of class "power.htest", a list of the arguments (including the computed one) augmented with method and note elements.

References

Newman (2001), pages 286 - 287

See Also

hazard.ratio.test

Examples

## Example 14.4
power.hr.test(hr = 2, p1 = 0.251, pi2 = 0.174, power = 0.8)
power.hr.test(n = 414, hr = 2, p1 = 0.251, pi2 = 0.174)

clayford/bme documentation built on May 13, 2019, 7:37 p.m.