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Using baseline data to design a group randomized trial
Author(s) -
Hughes James P.
Publication year - 2005
Publication title -
statistics in medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.996
H-Index - 183
eISSN - 1097-0258
pISSN - 0277-6715
DOI - 10.1002/sim.2080
Subject(s) - baseline (sea) , randomized controlled trial , computer science , group (periodic table) , statistics , medicine , mathematics , chemistry , oceanography , organic chemistry , geology
Group randomized trials (GRT) are often designed with relatively little preliminary data available to estimate key parameters. In this paper, however, the opposite situation is considered—very good baseline data are available on the primary outcome of interest. These data can then be used to inform key design and analysis decisions such as (i) should the trial be designed as an unmatched or pair‐matched study, or stratified in some other fashion; (ii) is analysis of ‘change from baseline’ preferable to using end‐of‐study data alone; and (iii) what power might be expected by pursuing these various strategies. The results are applied to a GRT for sexually transmitted diseases prevention in Peru. Copyright © 2005 John Wiley & Sons, Ltd.