The use of an alcometer in clinical forensic practice

Forensic physicians are at times required to provide a professional opinion on a person's degree of intoxication through alcohol, particularly with regard to fitness for interview by the police. Inherent to these assessments is an estimation of the blood alcohol concentration (BAC). Most forensic physicians rely on taking a history regarding recent alcohol consumption and a clinical assessment to estimate the BAC. We report a study in which the BAC of 118 detainees was estimated and compared with the BAC measured by an alcometer. Our estimations were accurate in 66% of cases. Most errors resulted from underestimating the BAC. Additionally, we attempted to determine fitness for interview using a single measurement of the BAC without a clinical assessment. 19% of those who were assessed as unfit for interview had a BAC of less than the UK legal limit for driving (currently 80 mg%) and 37% considered fit, had a BAC above that level. We conclude that the routine use of alcometers would enhance the practice of forensic medicine but could not replace its role in the assessment of levels of alcohol intoxication.