Evaluation of the Urine Drug Abuse Screening Tests

Background: Substance use is an important public health problem and increasing all over the world. Different methods have been defined for drug abuse testing in medical laboratories. We aimed to compare two urine drug screening methods with liquid chromatography -tandem mass spectrometry (LCMS/MS). Methods: A total of 102 patients' urine samples were analyzed by test dip card and EMIT (enzyme multiplied immunoassay technique). Randomly selected samples (n = 51; 50%) were also analyzed by LCMS/MS as the reference method. Results: The drug results of all patients analyzed with the test card and EMIT were compatible. Nine of 51 samples (18%) were negative according to all methods. The sensitivity and specificity percentages of AMP, COC, MDMA, OPI/MOP, and THC using test card were 70/96, 100/100, 47/100, 50/100, and 80/85, respectively. Similarly, the sensitivity and specificity percentages of AMP, COC, MDMA, OPI/MOP, and THC using EMIT were 76/97, 100/100, 57/100, 56/100, and 76/91, respectively. Conclusions: The performances of two immunochemical methods were similar for AMP, BZO, COC, MDMA, OPI/MOP, and THC whereas lower than LCMS/MS for AMP, MDMA, OPI/MOP, and THC. A sample that is positive according to any immunochemical method should be confirmed by definitive techniques such as LCMS/MS. (Clin. Lab. 2024;70:533-541. DOI: 10.7754/Clin.Lab.2023.230812)