title: Accuracy of common drug screen tests.
abstract: Forty consecutive urine specimens, obtained from patients seen in the emergency center, positive for either cocaine and/or marijuana, were analyzed using five methods of analysis. A new latex agglutination inhibition assay, Abuscreen OnTrak, (Roche Diagnostic Systems, Nutley, NJ), was compared with four other drug abuse assays: mass spectrometry, (Hewlett-Packard Co, Richardson, TX); an automated homogeneous enzyme immunoassay technique, ETS System, (Syva Co, Palo Alto, CA); a manual enzyme multiplied immunoassay technique; EMIT-st, (Syva); and a fluorescence polarization immunoassay, TDx, (Abbott Laboratories, Chicago, IL). For statistical purposes, mass spectrometry was the reference point for the presence or absence of a specific substance. All instrument sensitivities, with the exception of mass spectrometry, were set with the same "cut off" point of 100 micrograms/L for marijuana and 300 micrograms/L for cocaine and its metabolites. Efficiency in the detection of cocaine and its metabolites was 95% by all methods. Efficiency for the detection of marijuana and its metabolites ranged from 70% (Roche's OnTrak) to 90% (Syva's ETS). Simple to use, assays of minimal cost are presently available for rapid, accurate drug of abuse screening.
authors.affiliation: Department of Pathology, University of Texas Health Science Center, San Antonio 78284-7750.
authors.forename: J G
authors.initials: JG
authors.lastname: Schwartz
authors.forename: P R
authors.initials: PR
authors.lastname: Zollars
authors.forename: A O
authors.initials: AO
authors.lastname: Okorodudu
authors.forename: J J
authors.initials: JJ
authors.lastname: Carnahan
authors.forename: J E
authors.initials: JE
authors.lastname: Wallace
authors.forename: J E
authors.initials: JE
authors.lastname: Briggs
mesh_terms: D005069:Evaluation Studies as Topic; D016231:Fluorescence Polarization Immunoassay / Q000592:standards; D006801:Humans; D007118:Immunoassay / Q000592:standards; D007841:Latex Fixation Tests / Q000592:standards; D008403:Mass Screening / Q000295:instrumentation / Q000379:methods / Q000592:standards*; D013058:Mass Spectrometry / Q000592:standards; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D015813:Substance Abuse Detection / Q000295:instrumentation / Q000379:methods / Q000592:standards*; D019966:Substance-Related Disorders / Q000453:epidemiology / Q000517:prevention & control / Q000652:urine*