HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Submit a response Purchase Article View Shopping Cart Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Services Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via ISI Web of Science (27) Citing Articles via Google Scholar Google Scholar Articles by Varnell, S. P. Articles by Blitstein, J. L. Search for Related Content PubMed PubMed Citation Articles by Varnell, S. P. Articles by Blitstein, J. L. Related Collections Other Statistics/Evaluation/Research

Sherri P. Varnell, PhD, David M. Murray, PhD, Jessica B. Janega, MS and Jonathan L. Blitstein, MS

Sherri P. Varnell is with NorthropGrumman Mission Systems, Atlanta, Ga. David M. Murray, Jessica B. Janega, and Jonathan L. Blitstein are with the Department of Psychology, College of Arts and Sciences, University of Memphis, Tenn.

Correspondence: Requests for reprints should be sent to David M. Murray, PhD, 3693 Norriswood, 202 Psychology Building, Memphis, TN 38134 (e-mail: d.murray{at}mail.psyc.memphis.edu).

We reviewed group-randomized trials (GRTs) published in the American Journal of Public Health and Preventive Medicine from 1998 through 2002 and estimated the proportion of GRTs that employ appropriate methods for design and analysis.

Of 60 articles, 9 (15.0%) reported evidence of using appropriate methods for sample size estimation. Of 59 articles in the analytic review, 27 (45.8%) reported at least 1 inappropriate analysis and 12 (20.3%) reported only inappropriate analyses. Nineteen (32.2%) reported analyses at an individual or subgroup level, ignoring group, or included group as a fixed effect.

Hence increased vigilance is needed to ensure that appropriate methods for GRTs are employed and that results based on inappropriate methods are not published.

This article has been cited by other articles:

				S. Eldridge, D. Ashby, C. Bennett, M. Wakelin, and G. Feder Internal and external validity of cluster randomised trials: systematic review of recent trials BMJ, April 19, 2008; 336(7649): 876 - 880. [Abstract] [Full Text] [PDF]

				D. M. Murray, S. L. Pals, J. L. Blitstein, C. M. Alfano, and J. Lehman Design and Analysis of Group-Randomized Trials in Cancer: A Review of Current Practices J Natl Cancer Inst, April 2, 2008; 100(7): 483 - 491. [Abstract] [Full Text] [PDF]

				P. Z. Schochet Statistical Power for Random Assignment Evaluations of Education Programs Journal of Educational and Behavioral Statistics, March 1, 2008; 33(1): 62 - 87. [Abstract] [Full Text] [PDF]

				J. L. Blitstein, P. J. Hannan, D. M. Murray, and W. R. Shadish Increasing the Degrees of Freedom in Existing Group Randomized Trials: The df* Approach Eval Rev, June 1, 2005; 29(3): 241 - 267. [Abstract] [PDF]

				J. L. Blitstein, D. M. Murray, P. J. Hannan, and W. R. Shadish Increasing the Degrees of Freedom in Future Group Randomized Trials: The df* Approach Eval Rev, June 1, 2005; 29(3): 268 - 286. [Abstract] [PDF]

				B. C. Lee, J. D. Westaby, and R. L. Berg Impact of a National Rural Youth Health and Safety Initiative: Results from a Randomized Controlled Trial Am J Public Health, October 1, 2004; 94(10): 1743 - 1749. [Abstract] [Full Text] [PDF]

				S. J. Zyzanski, S. A. Flocke, and L. M. Dickinson On the Nature and Analysis of Clustered Data Ann. Fam. Med, May 1, 2004; 2(3): 199 - 200. [Full Text] [PDF]

				D. C. Des Jarlais, C. Lyles, N. Crepaz, and the TREND Group Improving the Reporting Quality of Nonrandomized Evaluations of Behavioral and Public Health Interventions: The TREND Statement Am J Public Health, March 1, 2004; 94(3): 361 - 366. [Abstract] [Full Text] [PDF]

				D. M. Murray, S. P. Varnell, and J. L. Blitstein Design and Analysis of Group-Randomized Trials: A Review of Recent Methodological Developments Am J Public Health, March 1, 2004; 94(3): 423 - 432. [Abstract] [Full Text] [PDF]