Korpi‐Steiner, Nichole

Abstract Background Urine drug testing (UDT) is a standard practice used for monitoring controlled and illicit substances in ambulatory care patients. Point-of-care (POC) UDTs are useful tools that allow for drug identification within minutes, providing rapid and objective diagnostic assistance for clinicians. The objective of this study was to evaluate the performance characteristics of 3 different POC UDT devices compared to reference methods. Methods A total of 106 residual urine specimens were collected to evaluate the 3 POC UDT devices: the Profile®-V MEDTOX Scan® drugs of abuse test, Quidel Triage® TOX Drug screen, and Quidel Triage Rapid OXY-BUP-MDMA panel. Device performance was assessed by their ability to identify drug classes/compounds compared to manufacturer and reference method (mass spectrometry) cutoffs. Results The results from quantitative mass spectrometry showed that 77% (84/106) of the samples were positive for one or more drugs. Each device had variable performance across each drug class. Overall, the specificity of the Profile-V MEDTOX Scan test was 90.1%, while the Quidel Triage TOX Drug Screen and Rapid OXY-BUP-MDMA devices had specificities of 89.0% and 50.0% using their respective manufacturer-stated cutoffs. Overall sensitivity was determined to be 98.6%, 97.0%, and 100% for the Profile-V MEDTOX Scan, Quidel Triage TOX Drug Screen, and Rapid OXY-BUP-MDMA, respectively. Conclusions Of the 3 POC UDT devices evaluated, the Profile-V MEDTOX Scan demonstrated the best overall sensitivity and specificity compared to reference methods. False positive and negative results are possible with UDTs, ultimately the best device may depend on patient population and drugs of interest.

Abstract We compared the clinical concordance of estimated glomerular filtration rate (eGFR) based on 3 whole blood creatinine assays with the eGFR calculated from a reference plasma creatinine assay. Whole blood creatinine on the Radiometer ABL800 FLEX (Radiometer A/S, Bronshoj, Denmark) demonstrated the best correlation and concordance to plasma creatinine/eGFR compared with the i-STAT (i-STAT, East Windsor, NJ) and StatSensor (Nova Biomedical, Waltham, MA). The i-STAT had better sensitivity (compared with Radiometer) but poorer specificity for prediction of plasma eGFR less than 60 mL/min/1.73 m2. The StatSensor demonstrated lower concordance of whole blood to plasma eGFR but offered a slope and an intercept offset feature that partially compensates for this effect. The optimal device for use in rapid determination of eGFR from whole blood creatinine may depend on whether it is more important in a given practice to optimize sensitivity, specificity, or overall concordance for determining plasma eGFR less than 60 mL/min/1.73 m2.