How to Test: Point of Care vs Lab-based Testing

Why is urine the preferred biological specimen over hair or blood?  And, how does point of care (POC) differ from lab-based urine drug testing (UDT)?  These are the topics Doctors Akbik, Clark, Heit, and McCarberg discuss in Drug Testing in Pain Management.

Urine is the gold standard of biological specimens for drug testing.

• Urine offers a longer window of detection* period when compared to blood.
• Urine drug testing is less costly than hair or blood serum testing.
• Urine collection for UDT is non-invasive, patient-friendly, and convenient.

*The window of detection is the length of time a substance (eg, drug) is detectable in a specimen.

Difference between Point of Care and Lab-based UDT
Point of care and lab-based UDT are the two primary types of urine drug tests.  POC testing involves collecting the patient’s urine in a specific cup designed for UDT.  The specimen is analyzed in the physician’s office using a color-banded or numbered dipstick enabling visual results.  The type of test is an immunoassay, a biochemical test that uses an antibody as a reagent.

Lab-based urine drug testing makes use of liquid chromatography-mass spectrometry and/or gas chromatography to analyze the patient’s specimen.  These techniques are highly sensitive and accurately and definitively identify substances (eg, synthetic opioid) and metabolites.

Table 1. Comparing Point of Care and Lab-based Urine Drug Testing

UDT Results Are Important to You and Your Patients
Accurate and timely results from urine drug testing are critical to an opioid therapy plan for patients in chronic pain.

Point of care UDT provides a primary care physician rapid results that are especially useful in an urgent situation.  Unfortunately, POC lacks the sensitivity lab-based testing offers, including a very important resource—the toxicologist.  Toxicology support is a vital benefit to assist physician interpretation and understanding of UDT results.

Introduction: Drug Testing in Pain Management