re.clustsize.cont

For a continuous outcome, computes the relative efficiency (ratio of the variances) of a cluster randomized
or multisite trial with varying cluster (site) sizes to that of a trial with constant cluster sizes,
assuming equal total number of subjects. This approximation may not be valid for all combinations of
parameters, for example when m.sd is large.

Power and sample size calculations for a variety of study designs and
outcomes. Methods include t tests, ANOVA (including tests for interactions,
simple effects and contrasts), proportions, categorical data (chi-square tests
and proportional odds), linear, logistic and Poisson regression, alternative
and coprimary endpoints, power for confidence intervals, correlation
coefficient tests, cluster randomized trials, individually randomized group
treatment trials, multisite trials, treatment-by-covariate interaction effects
and nonparametric tests of location. Utilities are provided for
computing various effect sizes. Companion package to the book
"Power and Sample Size in R", Crespi (2025, ISBN:9781138591622).
Further resources available at <https://powerandsamplesize.org/>.

Catherine M. Crespi

powertools

Power and Sample Size Tools

Zichen Liu

Kristen M. McGreevy

re.clustsize.cont function

<dl><dt>m</dt>
<dd>The number of subjects per cluster or the mean cluster size (if unequal number of participants per cluster).</dd>
<dt>m.sd</dt>
<dd>The standard deviation of cluster sizes (in case of unequal number of participants per cluster).</dd>
<dt>icc</dt>
<dd>The intraclass correlation coefficient. For a multisite trial this is icc1. For a CRT this is the average of the 2 icc's.</dd></dl>

Arguments

Relative efficiency of a cluster randomized or multisite trial with continuous outcome
with varying cluster sizes — re.clustsize.cont

<dl>

<dt>m</dt>
<dd>The number of subjects per cluster or the mean cluster size (if unequal number of participants per cluster).</dd>


<dt>m.sd</dt>
<dd>The standard deviation of cluster sizes (in case of unequal number of participants per cluster).</dd>


<dt>icc</dt>
<dd>The intraclass correlation coefficient. For a multisite trial this is icc1. For a CRT this is the average of the 2 icc's.</dd>

</dl>

re.clustsize.cont: Relative efficiency of a cluster randomized or multisite trial with continuous outcome with varying cluster sizes

Description

Usage

Value

Arguments

Examples