Sizing a trial to alter the trajectory of health behaviours: Methods, parameter estimates, and their application

David M. Murray, Jonathan L. Blitstein, Peter J Hannan, William L. Baker, Leslie A. Lytle

Research output: Contribution to journalArticlepeer-review

18 Scopus citations

Abstract

Group-randomized trials often involve repeat observations on the same participants. When there are no more than two observations from each participant, standard mixed-model regression methods for a pretest-posttest design can be used. When there are more than two observations from each participant, random coefficients models may be useful. This paper describes the random coefficients analysis appropriate to data from an extended nested cohort design and presents the methods for power analysis and sample size calculations based on that analysis. We provide estimates for the parameters required for those calculations for a number of adolescent health behaviours. We also show how the estimates can be used to plan a future trial.

Original languageEnglish (US)
Pages (from-to)2297-2316
Number of pages20
JournalStatistics in Medicine
Volume26
Issue number11
DOIs
StatePublished - May 20 2007

Keywords

  • Group-randomized trial
  • Power
  • Random coefficients analysis
  • Variance components

Fingerprint Dive into the research topics of 'Sizing a trial to alter the trajectory of health behaviours: Methods, parameter estimates, and their application'. Together they form a unique fingerprint.

Cite this