Does Positive Blood Testing, Urine Testing or Hair Testing Indicates Impairment?
Positive hair samples for drugs of abuse does not equate with impairment, it only can determine that in the past a patient has been using drugs (with a given limit). The presence of drugs of abuse in the urine can absolutely not be equated with impairment, but rather use in the last day or several days, and in some extreme cases a week. The presence of drugs or their metabolites in the blood testing does not prove impairment, because there is no scientific data to extrapolate the exact level of illegal drugs that will impair a specific user. That type of extrapolation has been made only for alcohol, which has a legal definition in driving statures, Federal and State, as well as medical forensic extrapolation formulas. (For instance, the blood alcohol disappearance curve.) Commonly a forensic toxicologist and forensic physician will be asked to determine whether urine positivity for illegal drugs indicates that that person was Aunder the influence@ or Aintoxicated@ when an accident occu
