We also investigated the main sources of racial and ethnic misclassification and the effect of health care utilization on the quality of race and ethnicity information, taking into consideration that information in the electronic health record of an integrated health care system is constantly updated.
This may support the hypothesis that duration of PCB exposure, rather than a specific time period, is most critical to hearing development; or it may simply be that the postnatal average metric reduces PCB exposure misclassification and thus effect estimate attenuation toward the null hypothesis.
Concerning risk estimates, selection bias, misclassification bias, and effects of the disease on mobile phone use could have reduced estimates, and recall bias may have led to spuriously increased risks.
This approach was used only to approximate short term residual and misclassification effects, and should not be interpreted as a measure of long term residual risk.
These issues include: case reports, study design, specificity of exposure, interview or recall bias, misclassification of occupation or exposure, confounding multiple exposures, confidence intervals and statistical power, selection of relevant studies, consistency of study results, study cohort definition, cohort membership misclassification, dilution effect, and subcohort or stratified analysis.
The limitations were as follows: the cross-sectional design does not allow causal conclusions; T2DM was based on a self-reported physician's diagnosis; administrative definitions of neighbourhoods could result in exposure misclassification and underestimation of neighbourhood effects; problem of residential selection.
This could lead to exposure misclassification and underestimation of neighbourhood effects.
These sources of information bias were most likely independent of temperature and can be classified as non-differential misclassification and will produce smaller effects than actually (attenuation).
Even though all observers (ergonomists) were trained to the point that their judgments were standardized, the relatively large number of observers involved in the study might have negatively influenced inter-observer reliability, leading to an increased risk of non-dependent misclassification and thus dilution of effects.
