Sample size formula with a continuous outcome for unequal group sizes and unequal variances

Authors
Schouten, HJA
Citation
Hja. Schouten, Sample size formula with a continuous outcome for unequal group sizes and unequal variances, STAT MED, 18(1), 1999, pp. 87-91
Citations number
8
Categorie Soggetti
General & Internal Medicine","Medical Research General Topics
Journal title
STATISTICS IN MEDICINE
ISSN journal
02776715 → ACNP
Volume
18
Issue
1
Year of publication
1999
Pages
87 - 91
Database
ISI
SICI code
0277-6715(19990115)18:1<87:SSFWAC>2.0.ZU;2-C
Abstract
Guenther derived a simple formula for the accurate computation of equal sam ple sizes when the two-sample t-test with pooled variance estimate is used. In the present paper, the Guenther formula is generalized to the case of u nequal sample sizes. In addition, the case of unequal variances is consider ed. Copyright (C) 1999 John Wiley & Sons, Ltd.