crt.parallel.bin: Power calculation for cluster randomized trial with binary outcome
Description
This function performs power and sample size calculations for a two-arm cluster randomized trial
with a binary outcome. It assumes the outcome analysis will be conducted using a mixed effect logistic
regression model that has a random intercept for cluster. Equal allocation of clusters to arms
is assumed. Can solve for power, J, m or alpha.
Usage
crt.parallel.bin(
m = NULL,
m.sd = 0,
J = NULL,
pc = NULL,
pt = NULL,
sigma.u = NULL,
alpha = 0.05,
power = NULL,
sides = 2,
v = FALSE
)
Value
A list of the arguments (including the computed one).
Arguments
m
The number of subjects per cluster.
m.sd
The standard deviation of cluster sizes (provide if unequal number of participants per cluster); defaults to 0.
J
The total number of clusters (over both arms).
pc
The probability of the outcome in control clusters.
pt
The probability of the outcome in treatment clusters.
sigma.u
Standard deviation of the cluster random effect (random intercept).
alpha
The significance level (type 1 error rate); defaults to 0.05.
power
The specified level of power.
sides
Either 1 or 2 (default) to specify a one- or two- sided hypothesis test.
v
Either TRUE for verbose output or FALSE (default) to output computed argument only.
Details
For help selecting a reasonable value for sigma.u, consider using the crt.varexplore function.