A menu-driven facility for sample-size calculations in cluster randomized controlled trials

Karla Hemming () and Jen Marsh ()
Additional contact information
Karla Hemming: University of Birmingham
Jen Marsh: University of Birmingham

Stata Journal, 2013, vol. 13, issue 1, 114-135

Abstract: We introduce the Stata menu-driven command clustersampsi, which calculates sample sizes, detectable differences, and power for cluster randomized controlled trials. The command permits continuous, binary, and rate outcomes (with normal approximations) for comparisons of two-sided tests in two equal-sized arms. The command allows for specification of the number of clusters available, or the cluster size, or the average cluster size along with an estimate of the variation of cluster sizes. When the number of clusters available is insufficient to detect the required difference at the prespecified power, clustersampsi will return the minimum number of clusters required under the prespecified design along with the minimum detectable difference and maximum achievable power (both for the prespecified number of clusters). Cluster heterogeneity can be parameterized by using either the intracluster correlation or the coefficient of variation. The command is illustrated via examples. Copyright 2013 by StataCorp LP.

Keywords: clustersampsi; sample size; cluster randomized controlled trials; minimum detectable difference; maximum achievable power (search for similar items in EconPapers)
Date: 2013
Note: to access software from within Stata, net describe http://www.stata-journal.com/software/sj13-1/st0286/
References: View references in EconPapers View complete reference list from CitEc
Citations: View citations in EconPapers (12)

Downloads: (external link)
http://www.stata-journal.com/article.html?article=st0286 link to article purchase

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:tsj:stataj:v:13:y:2013:i:1:p:114-135

Ordering information: This journal article can be ordered from
http://www.stata-journal.com/subscription.html

Access Statistics for this article

Stata Journal is currently edited by Nicholas J. Cox and Stephen P. Jenkins

More articles in Stata Journal from StataCorp LLC
Bibliographic data for series maintained by Christopher F. Baum () and Lisa Gilmore ().