title: Investigation into the suitability of a portable psychometric device to be used in the field: an illicit drugs field investigation.
abstract: BACKGROUND
  Driving performance is easily disrupted as a direct consequence of the use of alcohol, licit and illicit drugs. The use of such drugs has a high degree of correlation with increased accident risk. Europe wide research projects into drugged driving have called for the development of a portable objective device capable of screening those impaired through drug use which can be used at the roadside.
  
  
  OBJECTIVE
  This study investigated the cognitive and psychomotor performance of a cohort of polydrug drug users in field conditions. Volunteers completed a psychometric test battery on a hand held device in music festival conditions. The test battery comprised a critical tracking task (CTT) and a sustained attention to response task (SART). Volunteers also took a breathanalyser and provided a saliva sample for a DOA screen.
  
  
  RESULTS
  On the CTT significance was observed for tracking error following response to a peripheral stimulus in the high alcohol (>80 mg/100 ml) illicit drug group (p=0.0090) and approached significance for the low alcohol (<80 mg/100 ml) illicit drug group (p=0.088). For the SART, incorrect presses to the target stimulus was impaired for volunteers in both the low (<80 mg/100 ml) alcohol illicit drug group (p=0.0080) and the high alcohol (>80 mg/100 ml) illicit drug group (p=0.0415). Discrimination analysis demonstrated that the impairment device was able to discriminate between those individuals who had consumed neither alcohol nor drugs (94.12%), those in the low alcohol drug group (46.67%) and those in the high alcohol drug group (60.00%).
  
  
  CONCLUSIONS
  It is possible to derive an impairment ratio. Further research will demonstrate whether this device could significantly contribute to drug driving detection and road traffic safety.
authors.affiliation: HPRU Medical Research Centre, School of Biomedical and Molecular Sciences, University of Surrey, Guildford GU2 7XP, United Kingdom. a.degia@surrey.ac.uk
authors.forename: A
authors.initials: A
authors.lastname: Degia
authors.forename: R
authors.initials: R
authors.lastname: Meadows
authors.forename: S
authors.initials: S
authors.lastname: Johnsen
authors.forename: P
authors.initials: P
authors.lastname: Dixon
authors.forename: I
authors.initials: I
authors.lastname: Hindmarch
authors.forename: J
authors.initials: J
authors.lastname: Boyle
mesh_terms: D000293:Adolescent; D000328:Adult; D001288:Attention / Q000502:physiology; D001334:Automobile Driving / Q000331:legislation & jurisprudence; D001944:Breath Tests; D015331:Cohort Studies; D016002:Discriminant Analysis; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D011594:Psychometrics; D011597:Psychomotor Performance / Q000502:physiology; D011930:Reaction Time / Q000502:physiology; D015813:Substance Abuse Detection / Q000379:methods*; D019966:Substance-Related Disorders / Q000175:diagnosis* / Q000503:physiopathology*; D006113:United Kingdom