Therefore, if misclassification of intakes from the FFQ occurred, these would be expected to lead to a dilution of the magnitude of the associations.
In a prospective study, random misclassification of intakes at baseline or changes in diet during follow-up can result in 'regression-dilution bias' whereby the strength of disease risk associated with dietary intakes at baseline would be underestimated.
We cannot rule out potential misclassification of fish intake due to changes in fish intake during follow-up.
We cannot rule out the possibility that misclassification of alcohol intake affected our results given that under-reporting of alcohol consumption has often been reported.
Because most of the studies coffee was assessed through self-reported dietary questionnaires, misclassification of coffee intake is inevitable.
Misclassification of food intake may have occurred, although we used a validated food frequency questionnaire in the survey.
However, again some misclassification of dietary intake cannot be ruled out, such a misclassification is likely to be non-differential, and attenuating any true association.
Lack of associations between dietary factors and breast cancer risk could be the result of numerous sources of bias, including misclassification of dietary intake.
Because of the prospective design of the present study, any misclassification of alcohol intake would be non-differential and would tend to dilute the true association.
The FFQ is susceptible to measurement error and potential unquantified systematic biases that may have led to misclassification of dietary intake.
