IAfrac: Tools for weighted log-rank tests

Description Usage Arguments Details Author(s) References See Also

View source: R/Hasegawa2016.R

Calulcation of the information/covariance based on a presumed survival function under the alternative hypothesis.

1
2
3

I.1(rho, gamma, lambda, theta, eps, R, p, t.star)

I.1.cov(rho1, gamma1, rho2, gamma2, lambda, theta, eps, R, p, t.star)

`rho`	First power parameter for the Fleming-Harrington weight which weighs on the early departures: S(t^-)^ρ(1-S(t^-))^γ.
`gamma`	Second power parameter for the Fleming-Harrington weight which weighs on the late departures: S(t^-)^ρ(1-S(t^-))^γ.
`lambda`	Event hazard for the control arm.
`theta`	Hazard ratio after the change point (before the change point HR should be 1).
`eps`	Change point.
`R`	End of the accrual period.
`p`	Treatment assignment probability.
`t.star`	Time point we pause the study to check the cumulative information under the null.
`rho1`	First power parameters for the two Fleming-Harrington weights, defined for covariance calculation.
`gamma1`	Second power parameters for the two Fleming-Harrington weights, defined for covariance calculation.
`rho2`	First power parameters for the two Fleming-Harrington weights, defined for covariance calculation.
`gamma2`	Second power parameters for the two Fleming-Harrington weights, defined for covariance calculation.

This function is prepared to calculate the predicted information/covariance purely based on the assumed survival function under the alternaitve hypothesis: the control group is following an exponential distribution with hazard lambda, while the treatment group is following a piece-wise exponential distribution with same hazard before eps, but a hazard equals theta times the lambda after eps.

Lili Wang.

Hasegawa, T. (2016). Group sequential monitoring based on the weighted log‐rank test statistic with the Fleming–Harrington class of weights in cancer vaccine studies. Pharmaceutical statistics, 15(5), 412-419.

I.0

lilywang1988/IAfrac documentation built on March 11, 2021, 11:53 a.m.