title: Comparison of ethyl glucuronide in hair with self-reported alcohol consumption.
abstract: OBJECTIVE
  Ethyl glucuronide (EtG) in hair is a proposed biomarker for alcohol consumption. This study compares hair EtG concentrations with self-reported alcohol consumption data, in individuals with a range of alcohol use.
  
  
  METHODS
  Hair was collected from 100 participants with a range of alcohol use. Participants completed an Alcohol Use Disorders Identification Test C questionnaire to record alcohol consumption. Participants were categorized into one of the four groups: tee-totallers (consuming 0 units a week), lower-risk drinkers (1-21 units a week), increasing-risk drinkers' consuming (22-50 units a week) and high-risk drinkers (over 50 units a week). Hair from the proximal 3 cm was analysed for EtG using gas chromatography-mass spectrometry/mass spectrometry.
  
  
  RESULTS
  EtG was detected in 29 out of 100 hair samples. Based on the Society of Hair Testing (SOHT) threshold of 30 pg/mg EtG, the hair test identified alcohol consumption in 57.9% of high-risk drinkers, 45.5% of increasing-risk drinkers and only 9.8% of lower-risk drinkers. EtG sensitivity was highest for high-risk drinkers (consuming more than 50 units a week), identified to be 0.52 using a 30 pg/mg threshold and 0.58 using a 45 pg/mg threshold. A positive result is highly likely to indicate any drinking (positive predictive value, 1.00). A negative result does not provide good evidence for abstinence (negative predictive value, 0.23).
  
  
  CONCLUSIONS
  EtG has been identified to be a low sensitivity marker that cannot be used quantitatively to determine alcohol exposure. EtG can be used qualitatively to indicate alcohol consumption with a positive result providing strong evidence for an individual drinking within the past 3 months.
authors.affiliation: Psychopharmacology Unit, University of Bristol, UK. rosie.lees@bristol.ac.uk
authors.forename: Rosemary
authors.initials: R
authors.lastname: Lees
authors.forename: Robert
authors.initials: R
authors.lastname: Kingston
authors.forename: Tim M
authors.initials: TM
authors.lastname: Williams
authors.forename: Graeme
authors.initials: G
authors.lastname: Henderson
authors.forename: Anne
authors.initials: A
authors.lastname: Lingford-Hughes
authors.forename: Matthew
authors.initials: M
authors.lastname: Hickman
mesh_terms: D000428:Alcohol Drinking; D015415:Biomarkers; D008401:Gas Chromatography-Mass Spectrometry; D005965:Glucuronates / Q000032:analysis*; D006197:Hair / Q000737:chemistry*; D006801:Humans; D011237:Predictive Value of Tests; D057566:Self Report; D012680:Sensitivity and Specificity; D015813:Substance Abuse Detection / Q000379:methods*
chemical_list: D015415:Biomarkers; D005965:Glucuronates; C093924:ethyl glucuronide