The impact of stratification by implausible energy reporting status on estimates of diet-health relationships

Publisher:
Wiley
Publication Type:
Journal Article
Citation:
Biometrical Journal, 2016, 58 pp. 1538 - 1551
Issue Date:
2016-01-01
Full metadata record
Files in This Item:
Filename Description Size
C:\Users\108848\Downloads\Tooze_et_al-2016-Biometrical_Journal.pdfPublished Version125.97 kB
Adobe PDF
© 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.The food frequency questionnaire (FFQ) is known to be prone to measurement error. Researchers have suggested excluding implausible energy reporters (IERs) of FFQ total energy when examining the relationship between a health outcome and FFQ-reported intake to obtain less biased estimates of the effect of the error-prone measure of exposure; however, the statistical properties of stratifying by IER status have not been studied. Under certain assumptions, including nondifferential error, we show that when stratifying by IER status, the attenuation of the estimated relative risk in the stratified models will be either greater or less in both strata (implausible and plausible reporters) than for the nonstratified model, contrary to the common belief that the attenuation will be less among plausible reporters and greater among IERs. Whether there is more or less attenuation depends on the pairwise correlations between true exposure, observed exposure, and the stratification variable. Thus exclusion of IERs is inadvisable but stratification by IER status can sometimes help. We also address the case of differential error. Examples from the Observing Protein and Energy Nutrition Study and simulations illustrate these results.
Please use this identifier to cite or link to this item: