title: A hybrid approach to urine drug testing using high-resolution mass spectrometry and select immunoassays.
abstract: OBJECTIVE
  The major objective of this research was to propose a simplified approach for the evaluation of medication adherence in chronic pain management patients, using liquid chromatography time-of-flight (TOF) mass spectrometry, performed in parallel with select homogeneous enzyme immunoassays (HEIAs). We called it a "hybrid" approach to urine drug testing.
  
  
  METHODS
  The hybrid approach was defined based on anticipated positivity rates, availability of commercial reagents for HEIAs, and assay performance, particularly analytical sensitivity and specificity for drug(s) of interest. Subsequent to implementation of the hybrid approach, time to result was compared with that observed with other urine drug testing approaches.
  
  
  RESULTS
  Opioids, benzodiazepines, zolpidem, amphetamine-like stimulants, and methylphenidate metabolite were detected by TOF mass spectrometry to maximize specificity and sensitivity of these 37 drug analytes. Barbiturates, cannabinoid metabolite, carisoprodol, cocaine metabolite, ethyl glucuronide, methadone, phencyclidine, propoxyphene, and tramadol were detected by HEIAs that performed adequately and/or for which positivity rates were very low. Time to result was significantly reduced compared with the traditional approach.
  
  
  CONCLUSIONS
  The hybrid approach to urine drug testing provides a simplified and analytically specific testing process that minimizes the need for secondary confirmation.
authors.affiliation: From the ARUP Institute for Clinical and Experimental Pathology, Salt Lake City, UT; Department of Pathology, University of Utah School of Medicine, Salt Lake City; and gwen.mcmillin@aruplab.com.
authors.forename: Gwendolyn A
authors.initials: GA
authors.lastname: McMillin
authors.affiliation: From the ARUP Institute for Clinical and Experimental Pathology, Salt Lake City, UT;
authors.forename: Stephanie J
authors.initials: SJ
authors.lastname: Marin
authors.affiliation: From the ARUP Institute for Clinical and Experimental Pathology, Salt Lake City, UT; Department of Pathology, University of Utah School of Medicine, Salt Lake City; and.
authors.forename: Kamisha L
authors.initials: KL
authors.lastname: Johnson-Davis
authors.affiliation: ARUP Laboratories, Salt Lake City, UT.
authors.forename: Bryan G
authors.initials: BG
authors.lastname: Lawlor
authors.affiliation: From the ARUP Institute for Clinical and Experimental Pathology, Salt Lake City, UT; Department of Pathology, University of Utah School of Medicine, Salt Lake City; and.
authors.forename: Frederick G
authors.initials: FG
authors.lastname: Strathmann
mesh_terms: D000700:Analgesics / Q000627:therapeutic use / Q000652:urine*; D059350:Chronic Pain / Q000188:drug therapy*; D006801:Humans; D007118:Immunoassay; D055118:Medication Adherence; D012189:Retrospective Studies; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D015813:Substance Abuse Detection / Q000379:methods*
chemical_list: D000700:Analgesics
keywords: Adherence testing; LC-TOF/MS; Pain management