Fuel-cell breathalyser use for field research on alcohol intoxication: an independent psychometric evaluation.

Background. Several field studies have used fuel-cell breathalysers (FCB) to investigate the prevalence of alcohol intoxication. However, there is a lack of evidence evaluating the psychometric properties of these breathalysers outside of the forensic disciplines. Methods. The current research describes four studies designed that assess the reliability and validity of portable platinum FCBs for research on alcohol intoxication. Utilising the Alcolizer LE5 breathalyser and, to a lesser degree, the Lifeloc FC-20 and the Lion Intoxilyzer 8000, each study sampled patrons frequenting popular night-time entertainment districts with varying levels of alcohol intoxication. Results. Study one and two found excellent test-retest reliability and inter-instrument reliability for FCBs. Study three and four provided evidence to support the convergent validity of the two FCBs (the LE5 with the FC20), and with an evidential breathalyser (i.e., the Lion Intoxilyzer 8000; EB). Discussion. A 93-97 % agreement rate between breathalyser readings was found across the four studies. Portable FCB are recommended as a reliable and valid instrument for research designs requiring quick alcohol intoxication estimations in large populations. Strategies to enhance reliable and valid readings are provided for field researchers.