Several factors including underdosing, inappropriate dosing, variable absorption of the prodrug, variable clearance of the active metabolite, potential drug-drug interactions, P2Y12 receptor variability, and genetic polymorphisms of cytochrome P450 isoenzymes are possible mechanisms of clopidogrel resistance [ 11].
To determine ethanol in human post-mortem blood samples is problematic, largely due to the inappropriate and variable methods of preserving and storing, which can cause decomposition and loss of alcohol concentration.
However, if the temperature measure was 'too coarse' and hence an inappropriate environmental variable, individual plasticity estimates could be downwardly biased.
Inappropriate selection of variables is an important and common cause of poor model performance in this situation.
Such statistical tests are inappropriate when the variables under investigation are highly correlated, however, as is the case with the prognostic indicators for breast cancer [ 27].
A bivariate analysis was carried out between the outcome variable (frequency of inappropriate days) and each variable included in OPTIGOV© and AEP surveys.
All the studies published, including that of Raymond et al., used historical controls (before versus after studies), which is inappropriate considering the variable nature of bacterial epidemiology.
However, age was also a modifier of the association between other independent variables and inappropriate use of ER (P value for interaction = 0.04), which suggests that the determinants of inappropriate ER use may differ among younger patients (15 and 49 years) and older patients- 50 years or more).
Both methods, however, are either computationally prohibitive for robust optimization or inappropriate for correlated random variables.
But when one switching period control is adopted and the system loses stability under inappropriate parameters, the state variables will be unsymmetrical.
