Study design for epidemiologic studies with measurement error.

Exposure measurement error in epidemiological studies is recognized as a feature that must be considered because of the potential bias that can result in estimates of the exposure-disease association. Most of the work to date has focused on methods of analysis that adjust for the resultant bias, but the implications of this work to the design of epidemiologic studies is not as well understood. An overview of the issues involved in the use of methods for dealing with errors in exposure information is discussed along with some design options that have been proposed for providing information necessary for their use. Validation studies compare somewhat crude and inexpensive measures of exposure to a gold standard, and study designs that incorporate these into the overall plan can realize some advantages in terms of cost. In addition, repeated assessments of exposure can realize efficiency for measures of exposure that are unbiased. However, much work remains to be done in the development of efficient designs for studying disease aetiology and prevention.