That could result in an underestimation of the effect.
When exposure or intervention has a non-null effect on disease outcome, omitted covariates lead to underestimation of the effect of exposure or intervention.
In addition, the endogeneity of entry seems to cause underestimation of the effect for men.
Pooling data from both time-points ignores basic pathophysiological knowledge and additionally is likely to result in an underestimation of the effect size. .
This shows that excluding data during and immediately after P-gp inhibition leads to an underestimation of the effect of P-gp inhibition on brain concentrations of P-gp substrates.
Any misclassification is likely to be independent of birth weight and lead to an underestimation of the effect.
First, it cannot be excluded that hyaluronidase remains stable in the subcutaneous Alzet minipump, which may have resulted in an underestimation of the effect of hyaluronidase during the 4 week course of the experiment.
Attrition bias may have led to underestimation of the effect.
This error might have lead to an underestimation of the effect of an overall PBDE exposure.
In both cases we would expect a nondifferential misclassification and thereby an underestimation of the effect.
The attrition may also have led to underestimation of the effect size in our longitudinal analyses.
