Performance of Five Non-Instrumented Urine Drug-Testing Devices with Challenging Near-Cutoff Specimens

Journal of Analytical Toxicology, Vol. 25, November/December2001 Performance of Five Non-Instrumented Urine Drug-TestingDeviceswith ChallengingNear-Cutoff Specimens* Biomedical Consulting, Palo Alto, California [ Abstract ] A comparison of five non-instrumented urine drug-testingdevices was performed usinga challenging clinical specimen set with drug concentrations close to the immunoassayscreeningcutoffs. The five deviceswere Syva RapidTestd.a.u. 8, Syva RapldCup d.a.u. 5, Roche TesTcup5, Biosite Triage, and Casco-Nerl microLINE Drug Screen Card. Sixty clinical specimensfor each of the five SAMHSA-specified drug categories were tested by both a scientist and a non-scientistwith each result independently read by both. All specimens were also tested on a benchtop automated immunoassay analyzer (Syva ETS using Emit d.a.u, reagents)for comparison and by gas chromatography-massspectrometry (GC-MS). The non-instrumenteddevicesdemonstrated an overall accuracy of 70% (66-74%), based on standard GC-MS confirmation cutoffs, comparable to the Syva ETS analyzer (80%). There was also little difference in overall accuracy between the scientist (71%) and non-scientist (69%), although the non-scientist reported 10 false-positive results (0.7% of 1490 total results or 3.8% of 260 results for drug-free specimens), and the scientist reported only 1 false-positive result (0.07% of 1490 total resultsor 0.38% of 260 resultsfor drug-free specimens).When device performance was assessedaccording to drug presence/absence criteria, accuracy generally improved with all devices demonstrating extremely high positive predictive values (0.98-1). Introduction There has been much recent interest in the utility of rapid, easy-to-use, non-instrumented urine drug-testing devices for a variety of clinical and non-clinical applications: emergency room (1-3), perinatal (4), drug treatment, regulated and nonregulated workplaces (5,6), children and students (7), a variety of criminal justice settings (8), drugged driving (9,10), and even in the home (11-13). Since their introduction in the 1980s, there have been numerous technological advancements and performance improvements. The current devices utilize 9This work was presented at the annual meeting of the Society of Forensic Toxicologists, San Juan, Puerto Rico, October 1999. Address correspondence to Dr. Leo Kadehjian, Biomedical Consulting, 765 Chimalus Drive, Polo Alto, CA 94306, 670 well-established immunoassay technologies with antigenantibody reactions in part occurring on chromatographic test strips and the test results being read visuallywithin a few minutes as the presence or absence of a colored line. The test strips also have control lines so each test is controlled. A wide variety of these devices is now available in both single- and multi-assay configurations and in different formats, such as cup-type devices where the specimen may be provided directly into the device, card- or cassette-type deviceswhere the specimen is applied to the enclosed test strip using a pipette, and dipstick-type devices where the test strip is immersed in an aliquot of the specimen. These devicesare generally easy to use and rapid with results generally available within 10 rain, and often within 5 min. The great interest in these devices is evidenced by the rapid proliferation of the variety of these devices and the numerous positive performance evaluations of these devices presented at scientific meetings and in scientific publications (14-34). Furthermore, the utility and application of these and other unit test devicesare undergoing active regulatory reviewby numerous agencies: the U.S. Food and Drug Administration (FDA) establishing regulatory clearance criteria for marketing, with at least one non-instrumented drug-testing device already cleared by the FDA for at-home use; the Substance Abuse and Mental Health Services Administration (SAMHSA) for potential application in federally regulated workplace drugtesting programs; a wide variety of criminal justice agencies; and laboratory accreditation and standards organizations such as the College of American Pathologists (CAP),the Healthcare Financing Administration (HCFA), and the National Committee for Clinical Laboratory Standards (NCCLS). However, there has been ongoing concern that these simple, visually read devices may not provide sufficient scientific or forensic accuracy for use in some of the mentioned applications. Currently, there appears to be a consensus that these devices' results should not be used without further confirmation testing, regardless of the setting. Although many of the published performance studies have found these devices to perform surprisingly well, some published studies have been critical of their performance (1,35-47). It is interesting to note that although these devices are now being widely used in Reproduction(photocopying)o~ editorialcontentof thisjournalis prohibitedwithoutpublisher'spermission. Leo J. Kadehjian t Journal of Analytical Toxicology, Vol. 25, November/December2001 Materials and Methods The five devices included in the study were Syva RapidTest d.a.u. 8, Syva RapidCup d.a.u. 5, Roche TesTcup 5, Biosite Triage, and Casco-Nerl microLINE Drug Screen Card. All devices were obtained directly from the respective manufacturers; the Syva RapidTestand Syva RapidCupwere provided at no cost, and the other devices were purchased. Product descriptions Syva RapidTest d.a.u. 8. This cassette-type device requires the dropwise addition of three drops of urine to each of the cassette's two specimen wells using the provided disposable squeeze-type plastic pipette. The specimen immediately wicks along the two parallel test strips, with each strip testing for four drugs. Each strip also has a single control line. Results are read between 5 and t0 rain. Positive results are indicated by the absence of a colored line across the test strip for each assay. This device required about 6 rain to perform each test. Syva RapidCup d.a.u. 5. This combination collection/test cup device has fivesingle-assay test strips built into the wall of the cup. Each strip also has a single control line. A specimen is provided directly into the collection/testing device and the cap is partly secured. The test is not activated until the cap is further screwed down to its full stop position. The cap has a tamper-evident ratcheting mechanism that precludes the cap from later being removed without evidence. The cap presses down a dual O-ring sealed plunger that delivers a small portion of the specimen to the test well in the base of the device, iso- lating the test aliquot from the remainder of the specimen. The test sample wicks up the test strips, and the results are read through the window in the side of the collection/test cup. Positive results are indicated by the absence of a colored line across the test strip. This device required about 4 min to perform each test. Roche TesTcup5. This combina (...truncated)