A compliance management organization model for drug screen delivery

Beyond Positive and Negative

Almost every drug screen result you see is reported as either “Negative” or “Positive.” Ultimately, that’s the question we need answered, but sometimes the laboratory sends us back results listed as something other than Negative or Positive. It’s important to understand what those remarks indicate, so let’s review the possibilities:

  1. Negative – the result of the client’s screen, on that specific specimen, does not show evidence of the detectable presence of any of the substances included in that particular panel.
  2. Positive – the result of the client’s screen, on that specific specimen, does show evidence of the detectable presence of one or more of the substances included in that particular panel. This evidence may not be problematical if there is an existing prescription for the ingested substance.
  3. Negative but dilute – both the creatinine and the specific gravity are abnormal. This cannot be considered a true negative because the urine is abnormal, but it should not be considered a true positive either as certain medical conditions and certain medications can lead to dilute urine.
  4. Positive but dilute – the urine was dilute, but not enough to dilute out the positive result. But because the urine is dilute, we are unable to tell whether or not the other drugs were positive or negative.
  5. Adulterated – an adulterant interfered with the result. This could be intentional on the part of the donor (adding bleach to the urine, drinking vinegar, other chemicals) or unintentional (blood in the urine, some medications).
  6. Substituted – both the creatinine and the specific gravity are so abnormal that the specimen is not consistent with human urine.
  7. Invalid – a screen can be Invalid for a number of reasons, among them:
    1. Adulteration
    2. Immunoassay interference – Note that it is possible for a screen to be positive or negative for one or more substances, but still show interference for another substance
    3. Abnormal physical characteristics of specimen