As in other observational studies, dietary data measured by FFQs are subject to measurement error; however, due the prospective design, misclassification is likely to be nondifferential, which is likely to bias results toward the null.
The non-differential measurement error, however, would lead the results toward the null values.
We cannot exclude the possibility of measurement error; however, in our validation study, the correlation coefficient was higher for unprocessed compared with processed red meat.
This is probably a result of the complex movement in the knee joint (superimposition of different movements); a measurement error however cannot be excluded.
Food-frequency questionnaires involve a certain degree of measurement error; however, the ability to allocate subjects into a broad dietary pattern is probably very strong.
The blood pressure measurements we used in this study were obtained as part of routine care and are subject to measurement error; however, any such error would most likely be non-differential and is unlikely affect our findings.
It reduces the chance of finding associations with external variables (also subject to measurement error); however, in a regression analysis, measurement error in the dependent variable does not introduce bias in the size of the regression coefficient.
The adjusted and two-stage models were essentially robust to measurement error; however, both the unadjusted and adjusted did not always produce unbiased estimates of parameters for all underlying DAGs, especially at different levels of α.
The main limitation of our study was the use of self-reported breastfeeding which may have led to measurement error; however, an earlier validation study by Kark et al. reported high concordance between breastfeeding derived from clinic records compared with an interview conducted 20 to 22 years later (Spearman P = 0.86) [ 29].
Firstly, in relation to the ascertainment of exposure, this was obtained from self-report and therefore was marginally prone to measurement error; however, validation of self-reported eating disorders in a subsample of Generation R women yielded very high levels of sensitivity and specificity.
