GeneticsDesign (version 1.40.0)

power.genotype.conti: power for genetic studies using baseline measure

Description

Estimate power for genetice studies using baseline measurements via simulation.

Usage

power.genotype.conti(N, Rep = 2000, alpha = 0.05, ...)
simu.genotype.conti(N, p=0.15, pi=0, me1=50, me2=me1, delta=-5, sd1=10, sd2=10, verbose=FALSE, minh=c('additive', 'dominant', 'recessive'), genotype.delta=TRUE, Factor=FALSE)

Arguments

N

total number of subjects

p

frequency of A (affected) allele

Rep

number of simulatin runs used to estimate power

alpha

significance level

pi

correlation coefficient

me1, me2

mean of control and treatment groups

delta

treatment/genotype effect

sd1,sd2

standard deviation of the control and treatment groups

minh

mode of inheritance, one of 'additive', 'dominant', or 'recessive'

genotype.delta

logical indicating whether the treatment effect occurs only for an individual genotype (genotype.delta=TRUE) or for all genotypes (genotype.delta=FALSE)

Factor

Should the simulated treatment variable 'Trt' be be treated as a factor variable (Factor=TRUE) or as a numeric variable (Factor=FALSE).

verbose

Should information about each simulated data set and model fit be displayed.

...

Arguments to be passed to simu.genotype.conti

Value

~Describe the value returned If it is a LIST, use

comp1

Description of 'comp1'

comp2

Description of 'comp2'

...

Details

References

Frison and Pocock (1992) "Repeated measures in clinical trials: analysis using mean summary statistics and its implications for design" Statistics in Medicine 11:1685-1704 Vickers (2001) "The use of percentage change from baseline as an outcome in a controlled trial is statistically inefficient: a simulation study" BMC Med Res Methodol. 2001; 1 (1): 6

See Also

power.casectrl

Examples

## Not run: 
#   # use defaults, 100 subjects
#   power.genotype.conti(N=100)
# 
#   # same calculation, specifying all values
#   power.genotype.conti(N=100, Rep=2000, p=0.15, pi=0, me1=50, me2=50, delta=-5,
#                        sd1=10, sd2=10, verbose=FALSE, minh='additive',
#                        genotype.delta=TRUE, Factor=FALSE) 
# 
#   # Show details for small simulation study
#   power.genotype.conti(N=10, verbose=TRUE)
# ## End(Not run)