Design and analysis of studies evaluating smoking cessation interventions where effects vary between practices or practitioners.

BACKGROUND: Patients grouped together in practices may share characteristics that cause them to have similar responses to an intervention. Sampling from such groups means that the power of a trial is less than when subjects are selected from the population at random. Knowledge of likely variation in...

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Bibliographic Details
Main Authors: Butler, C, Bachmann, M
Format: Journal article
Language:English
Published: 1996