title: Estimating the measurement uncertainty in forensic blood alcohol analysis.
abstract: For many reasons, forensic toxicologists are being asked to determine and report their measurement uncertainty in blood alcohol analysis. While understood conceptually, the elements and computations involved in determining measurement uncertainty are generally foreign to most forensic toxicologists. Several established and well-documented methods are available to determine and report the uncertainty in blood alcohol measurement. A straightforward bottom-up approach is presented that includes: (1) specifying the measurand, (2) identifying the major components of uncertainty, (3) quantifying the components, (4) statistically combining the components and (5) reporting the results. A hypothetical example is presented that employs reasonable estimates for forensic blood alcohol analysis assuming headspace gas chromatography. These computations are easily employed in spreadsheet programs as well. Determining and reporting measurement uncertainty is an important element in establishing fitness-for-purpose. Indeed, the demand for such computations and information from the forensic toxicologist will continue to increase.
authors.affiliation: Clearview Statistical Consulting, 20119 61st Avaenue SE, Snohomish, WA 98296, USA. rod.gullberg@gmail.com
authors.forename: Rod G
authors.initials: RG
authors.lastname: Gullberg
mesh_terms: D000428:Alcohol Drinking / Q000097:blood*; D002492:Central Nervous System Depressants / Q000097:blood*; D002849:Chromatography, Gas; D000431:Ethanol / Q000097:blood*; D053593:Forensic Toxicology / Q000379:methods; D006801:Humans; D015203:Reproducibility of Results; D015813:Substance Abuse Detection / Q000379:methods*; D035501:Uncertainty
chemical_list: D002492:Central Nervous System Depressants; D000431:Ethanol