title: Using ethyl glucuronide in urine to detect light and heavy drinking in alcohol dependent outpatients.
abstract: OBJECTIVE
  This study investigated which ethyl glucuronide immunoassay (EtG-I) cutoff best detects heavy versus light drinking over five days in alcohol dependent outpatients.
  
  
  METHODS
  A total of 121 adults with alcohol use disorders and co-occurring psychiatric disorders took part in an alcohol treatment study. Participants provided self-reported drinking data and urine samples three times per week for 16-weeks (total samples=2761). Agreement between low (100 ng/mL, 200 ng/mL), and moderate (500 ng/mL) EtG-I cutoffs and light (women ≤3 standard drinks, men ≤4 standard drinks) and heavy drinking (women >3, men >4 standard drinks) were calculated over one to five days.
  
  
  RESULTS
  The 100 ng/mL cutoff detected >76% of light drinking for two days, and 66% at five days. The 100 ng/mL cutoff detected 84% (1 day) to 79% (5 days) of heavy drinking. The 200 ng/mL cutoff detected >55% of light drinking across five days and >66% of heavy drinking across five days. A 500 ng/mL cutoff identified 68% of light drinking and 78% of heavy drinking for one day, with detection of light (2-5 days <58%) and heavy drinking (2-5 days <71%) decreasing thereafter. Relative to 100 ng/mL, the 200 ng/mL and 500 ng/mL cutoffs were less likely to result in false positives.
  
  
  CONCLUSIONS
  An EtG-I cutoff of 100 ng/mL is most likely to detect heavy drinking for up to five days and any drinking during the previous two days. Cutoffs of ≥500 ng/mL are likely to only detect heavy drinking during the previous day.
authors.affiliation: Initiative for Research and Education to Advance Community Health (I-REACH), Washington State University, Box 1495, Spokane, WA 99210, United States. Electronic address: mmcdonell@wsu.edu.
authors.forename: Michael G
authors.initials: MG
authors.lastname: McDonell
authors.affiliation: Initiative for Research and Education to Advance Community Health (I-REACH), Washington State University, Box 1495, Spokane, WA 99210, United States.
authors.forename: Jordan
authors.initials: J
authors.lastname: Skalisky
authors.affiliation: Harborview Medical Center, Department of Psychiatry and Behavioral Sciences, University of Washington, Box 359911, 325 9th Avenue, Seattle, WA 98195, United States.
authors.forename: Emily
authors.initials: E
authors.lastname: Leickly
authors.affiliation: Program of Excellence in Addictions Research, Washington State University, PO Box 1495, Spokane, WA 99210 and Providence Medical Research Center, Providence Health Care, Spokane, WA 99210, United States.
authors.forename: Sterling
authors.initials: S
authors.lastname: McPherson
authors.affiliation: Harborview Medical Center, Department of Psychiatry and Behavioral Sciences, University of Washington, Box 359911, 325 9th Avenue, Seattle, WA 98195, United States.
authors.forename: Samuel
authors.initials: S
authors.lastname: Battalio
authors.affiliation: Initiative for Research and Education to Advance Community Health (I-REACH), Washington State University, Box 1495, Spokane, WA 99210, United States.
authors.forename: Jenny R
authors.initials: JR
authors.lastname: Nepom
authors.affiliation: Harborview Medical Center, Department of Psychiatry and Behavioral Sciences, University of Washington, Box 359911, 325 9th Avenue, Seattle, WA 98195, United States.
authors.forename: Debra
authors.initials: D
authors.lastname: Srebnik
authors.affiliation: Program of Excellence in Addictions Research, Washington State University, PO Box 1495, Spokane, WA 99210 and Providence Medical Research Center, Providence Health Care, Spokane, WA 99210, United States.
authors.forename: John
authors.initials: J
authors.lastname: Roll
authors.affiliation: Harborview Medical Center, Department of Psychiatry and Behavioral Sciences, University of Washington, Box 359911, 325 9th Avenue, Seattle, WA 98195, United States.
authors.forename: Richard K
authors.initials: RK
authors.lastname: Ries
mesh_terms: D000328:Adult; D000428:Alcohol Drinking / Q000652:urine*; D000437:Alcoholism / Q000175:diagnosis / Q000652:urine*; D015415:Biomarkers / Q000652:urine; D005260:Female; D005965:Glucuronates / Q000652:urine*; D006801:Humans; D007118:Immunoassay / Q000379:methods / Q000592:standards; D008297:Male; D008875:Middle Aged; D010045:Outpatients; D012015:Reference Standards; D057566:Self Report; D013053:Spectrophotometry; D015813:Substance Abuse Detection / Q000379:methods*
chemical_list: D015415:Biomarkers; D005965:Glucuronates; C093924:ethyl glucuronide
keywords: Alcohol biomarkers; Assessment of cut-off; Ethyl glucuronide in urine; Heavy drinking