This function calculates the asymptotic power and variance assuming that the survival distribution is a mixture of exponentials with rates and the censoring distribution is uniform on the interval (a,b).
asypow(n, theta, a, b, lambda0, q, p, alpha, z,exactvar)
Asymptotic power based on exact variance formula
Asymptotic power based on approximate variance formula
First term of asymptotic variance
Second term of asymptotic variance
Third term of the asymptotic variance (covariance)
Approximate asymptotic variance formula (=v1)
Exact asymptotic variance formula (=v1+v2+v12)
Difference between variances (=v2+v12)
Ratio of variances (=v1/(v1+v2+v12))
Sample size
Effect size (log genotype hazard ratio (GHR))
Censoring distribution parameter (assumed to be uniform on [a,b])
Censoring distribution parameter (assumed to be uniform on [a,b])
Baseline exponential hazard rate
Relative risk allele frequency
Relative genotype frequency
Nominal two-sided type I error rate
Genotype scores (right now only additive scores AA=0,AB=1,BB=2 generate correct power)
Indicator for using the exact variance formula
Kouros Owzar, Zhiguo Li, Nancy Cox, Sin-Ho Jung and Chanhee Yi
This function is called by sim.snp.expsurv.power to calculate the asymptotic variance (exact and approximate) formulas. It is not intended to be called directly by the user. To conduct power calculations, use sim.snp.expsurv.power or the convenience wrapper function survSNP.power.table.
Kouros Owzar, Zhiguo Li, Nancy Cox and Sin-Ho Jung. Power and Sample Size Calculations for SNP Association Studies with Censored Time-to-Event Outcomes. https://onlinelibrary.wiley.com/doi/full/10.1002/gepi.21645