Description Usage Arguments Details Value Author(s) References See Also Examples

This function calculates asymptotic and empirical power for SNP association studies

1 2 | ```
sim.snp.expsurv.power(GHR, B, n, raf, erate, pilm, lm, model, test, alpha,
exactvar = FALSE, interval = c(0, 10), rootint = c(0.1, 200))
``` |

`GHR` |
Genotype Hazard Ratio |

`B` |
Number of simulation replicates (set to 0 if no empirical calculations are desired) |

`n` |
Sample size |

`raf` |
Relative risk allele frequency |

`erate` |
Event Rate |

`pilm` |
Probability that the time-to-event is greater than lm |

`lm` |
Landmark time used for powering the study |

`model` |
True genetic risk model (choices are "additive", "recessive" or "dominant". For the asymptotic calculations only the "additive" should be used until further notice) |

`test` |
Hypothesized genetic risk model (choices are "additive", "recessive" or "dominant". For the asymptotic calculations only the "additive" should be used until further notice) |

`alpha` |
Nominal two-sided type I error rate |

`exactvar` |
Indicator for using the exact variance formula |

`interval` |
Interval to search for baseline hazard rate |

`rootint` |
Interval to search for censoring bound |

This function calculates asymptotic and empirical power for SNP association studies

This function returns a `data.frame`

with the following columns

`B` |
Number of simulation replicates |

`raf` |
Relative allelic frequency of the B allele |

`q0` |
Relative genotypic frequency for AA |

`q1` |
Relative genotypic frequency for AB |

`q2` |
Relative genotypic frequency for BB |

`lam0` |
Exponential hazard rate for P(T>t|AA) |

`lam1` |
Exponential hazard rate for P(T>t|AB) |

`lam2` |
Exponential hazard rate for P(T>t|BB) |

`GHR` |
Genotype Hazard Ratio |

`pilm` |
Probability that the time to event in the population exceeds the landmark lm: P(T>lm) |

`lm` |
Landmark (see pilm above) |

`model` |
The true genetic risk model |

`test` |
The hypothesized genetic risk model |

`a` |
Parameter for the censoring distribution (uniform on [a,b]) |

`b` |
Parameter for the censoring distribution (uniform on [a,b]) |

`erate` |
Event rate |

`n` |
Sample size |

`powB` |
Empirical Power |

`pow` |
Asymptotic Power based on the exact variance formula |

`pow0` |
Asymptotic Power based on the approximate variance formula |

`v1` |
First term of the variance (v1+v2+v12) |

`v2` |
Second term of the variance (v1+v2+v12) |

`v12` |
Third term (covariance) of the variance (v1+v2+v12) |

Kouros Owzar, Zhiguo Li, Nancy Cox, Sin-Ho Jung and Chanhee Yi

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. http://onlinelibrary.wiley.com/doi/10.1002/gepi.21645/abstract

1 2 3 4 5 6 | ```
# See vignette for examples including details on the example
# considered below
results<-sim.snp.expsurv.power(GHR=1.25, B=0, n=500, raf=0.1, erate=0.75, pilm=0.5,
lm=1, model="additive", test="additive", alpha=0.05)
results[,c("n","erate","alpha","pow0")]
``` |

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