Terminology -RT1

Point of Care Test kits (POCT) - Level 1 Certification

We understand that different terms are used throughout the drug testing industry. Because the terms we use in this training program may differ from the terms used by your organization, we have produced a short list of terminology to help understand this workbook content.

POCT device terms

POCT  =  Point-of-care-test  or  rapid drug test kit  or  instant test drug kit

POCT - is the abbreviation used for the term, point-of-care-test. This term is not exclusive to drug testing and is used with other technologies such as strep A, mono, and pregnancy to name just a few. In this training we will often use the term POCT to prevent confusion between the process of drug testing, lab testing and a drug test result.

POCT STRIPS - are white absorbent strips that are coated with chemicals and are designed to control the flow biological samples such as urine or oral fluid in a manner that supports a chemical reaction. The absorbent strips are the "active" elements of a POCT that produce results by displaying a series of lines.

POCT ASSAY (or ASSAY) - is the name normally designated to the testing process that is represented by a test and control line. For example: a THC assay is the test and control line of any marijuana POCT. You may also say, "How many assays are on that POCT?" or "This POCT has 5 assays"  If there are 5 drugs on the POCT, it has five assays.

RESULT WINDOW - is the area on a POCT  (actually located on the POCT strip) where the test and control lines should or will appear.

TEST LINE - is one of two lines that "may" appear on a valid POCT strip that is created by a chemical reaction. The line is a visual indication that drugs are or are not present in a donor sample. More information is available later in this training workbook.

CONTROL LINE - is one of two lines that "must" appear on a valid rapid drug test strip for the result to be  considered valid .


HOUSING - is the plastic components or shell of a POCT that does not include the rapid drug test strips. The housing is sometimes referred to as the format or test type such as dip card, cup or cassette..

Rapid Test Kit Result terms

NEGATIVE RESULT - a result that is displayed when a sample is does NOT contain the target drug or the amount of target drug in the sample is below the cut-off level for easy assays.

 

NON-NEGATIVE RESULT - a result that is displayed when a sample does contains the target drug in an amount that exceeds the assay cut-off level. Non-Negative results should be confirmed by secondary testing at a certified lab using GC/MS, LC/MS or LC/MS/MS.

 

POSITIVE RESULT - a result that has been screened "and" confirmed at a certified laboratory using GC/MS, LC/MS or LC/MS/MS.  

FALSE POSITIVE RESULT - a result that incorrectly identifies a sample as non-negative when in fact the sample is negative. 

 

FALSE NEGATIVE RESULT - a result that incorrectly identifies a sample as negative when in fact the drug concentration exceeds the assay's cut-off threshold. 

PARENT DRUG (PARENT COMPOUND) - is the actual drug that is consumed by donors before it has been digested and/or metabolized by the human body. Some assays are designed to detect the parent drug and some are designed to detect metabolite. Some assays detect both.

 

DRUG METABOLITE - is the altered form of parent drug after it has been consumed and metabolized by the human body. Consumption or use can be eaten, smoked, injected or absorbed into the human body by a donor. 

TARGET DRUG  (or target drug metabolite) - is the main or primary compound targeted by the assay for detection. In both POCT and lab testing, a positive or negative is generally based on the presence or absence of a specific drug or drug metabolite with reference to a certain level. Both are generally referred to as TARGET DRUGS.

 

CUT-OFF LEVEL (or cut-off threshold) - is the minimum amount of drug or drug metabolite in a donor's urine or oral fluid sample necessary to change an assay result from a negative to non-negative (or positive) result. In most cases, this determining level is measured in nano-grams per milliliter (sometimes displayed as "ng/mL").

DRUG IMPOSTERS - a term we use to explain an element, compound or medication that has a similar impact on a POCT strip as does the target drug. Drug Imposters can cause assay test lines to become lighter than normal. In high enough concentrations or when combined with small traces of target drug, Drug Imposters can cause false positive results. 

 

FLUX - is the range in rapid drug testing cut-off level where a sample may produce either a positive or negative result. This occurs when drug concentrations are close to the testing cut-off levels and multiple metabolites or drug imposters are present. This can be as wide as 50% +/- the assay's cut-off level.

 

WINDOW OF ACCURACY - is the time period when a POCT will produce the most accurate results. For most urine POCTs, the window of accuracy starts when the donor sample has been in contact with the POCT strips for at least 5 minutes but no longer than 55 minutes (The window of Accuracy for Oral Fluid POCTs is 3-5 minutes longer or 10-60 minutes).

 

 

Tampering and Adulteration terms

ADULTERANT - any substance used in an attempt to alter, mask or dilute a donor’s biological sample in an effort to produce a false result. 

 

ADULTERATION TEST  (Specimen Validity Test - SVT)- chemical screening process to determine if a sample is consistent with normal, expected biological properties. The specimen validity tests (SVT) used in some SmartReader™ urine test kits are:

 

pH -  is a test that checks the acidity or alkalinity of a donor urine sample. Unadulterated urine samples should have a pH level between 4.5 - 9.0. It is important to test a urine sample immediately after collection as the pH will change overtime, especially if left at room temperature. The pH test is designed to detect old urine samples.

 

SPECIFIC GRAVITY (SG) -  is a test to verify that a urine sample has not been diluted by adding water or by overhydration. The normal range for specific gravity is between 1.003 - 1.030. The SG test is designed to detect donors that over-hydrate in an attempt to alter the result.

 

CREATINTINE (Cr) - is a test that verifies that a urine sample has a creatinine level greater than 19 mg/dL. If a urine sample contains a low level or lacks creatinine, the sample is most likely substituted or dilute. The Cr test is designed to detect non-urine donor samples.

END OF TERMINOLOGY