title: Laboratory and clinical evaluation of on-site urine drug testing.
abstract: OBJECTIVE
  Products for on-site urine drug testing offer the possibility to perform screening for drugs of abuse directly at the point-of-care. This is a well-established routine in emergency and dependency clinics but further evaluation of performance is needed due to inherent limitations with the available products.
  
  
  METHODS
  Urine drug testing by an on-site product was compared with routine laboratory methods. First, on-site testing was performed at the laboratory in addition to the routine method. Second, the on-site testing was performed at a dependency clinic and urine samples were subsequently sent to the laboratory for additional analytical investigation.
  
  
  RESULTS
  The on-site testing products did not perform with assigned cut-off levels. The subjective reading between the presence of a spot (i.e. negative test result) being present or no spot (positive result) was difficult in 3.2% of the cases, and occurred for all parameters. The tests performed more accurately in drug negative samples (specificity 96%) but less accurately for detecting positives (sensitivity 79%). Of all incorrect results by the on-site test the proportion of false negatives was 42%. The overall agreement between on-site and laboratory testing was 95% in the laboratory study and 98% in the clinical study.
  
  
  CONCLUSIONS
  Although a high degree of agreement was observed between on-site and routine laboratory urine drug testing, the performance of on-site testing was not acceptable due to significant number of false negative results. The limited sensitivity of on-site testing compared to laboratory testing reduces the applicability of these tests.
authors.affiliation: Department of Laboratory Medicine, Section of Clinical Pharmacology, Karolinska Institutet , Stockholm , Sweden.
authors.forename: Olof
authors.initials: O
authors.lastname: Beck
authors.forename: Sten
authors.initials: S
authors.lastname: Carlsson
authors.forename: Marinela
authors.initials: M
authors.lastname: Tusic
authors.forename: Robert
authors.initials: R
authors.lastname: Olsson
authors.forename: Lisa
authors.initials: L
authors.lastname: Franzen
authors.forename: Peter
authors.initials: P
authors.lastname: Hulten
mesh_terms: D000662:Amphetamines / Q000652:urine; D000701:Analgesics, Opioid / Q000652:urine; D001569:Benzodiazepines / Q000652:urine; D002047:Buprenorphine / Q000652:urine; D002186:Cannabinoids / Q000652:urine; D005069:Evaluation Studies as Topic; D005188:False Negative Reactions; D006801:Humans; D008691:Methadone / Q000652:urine; D012680:Sensitivity and Specificity; D015813:Substance Abuse Detection / Q000379:methods* / Q000592:standards; D014147:Tramadol / Q000652:urine
chemical_list: D000662:Amphetamines; D000701:Analgesics, Opioid; D002186:Cannabinoids; D001569:Benzodiazepines; D014147:Tramadol; D002047:Buprenorphine; D008691:Methadone
keywords: Point-of-care testing; drugs of abuse; on-site drug testing; urine toxicology