Problems of Forensic Sciences 2020 Vol. 122-123 (CXXII-CXXIII) 143-163
THE INFLUENCE OF PROSPECTIVE CALCULATION MODELS ON ACCURACY OF DETERMINING THE SOBRIETY STATE
Karolina SEKUŁA, Dominika JAMA, Dariusz ZUBA
Institute of Forensic Research, Kraków, Poland
Streszczenie
Forensic expert opinions in drink-driving cases may be based on calculations to predict blood alcohol concentration (BAC) at the time of an accident. Although experts use the same formulas to calculate the theoretical maximum alcohol concentration in the body, the conclusions are often different. This is due to various approaches to alcohol absorption in the body and to the difference between the theoretical and actual ethanol concentration. An analysis of publications on alcohol absorption shows that the time of alcohol absorption varies over a very wide range (from a few minutes to almost 3 hours). A wide range of alcohol absorption time results in different values of the gap between the theoretical and actual ethanol concentration (so-called alcohol deficit). Therefore, the use of a specific time of alcohol absorption or a specific value of the alcohol deficit in the calculations, due to the large inter-individual variance of these parameters, is practically impossible and would be based only on certain debatable assumptions.
In this study, the most common methods of alcohol calculations used by various experts were compared in order to choose an appropriate model of prospective estimation of alcohol content. These methods mainly differed in the time from which the elimination of alcohol was calculated. We analysed 32 cases of alcohol consumption by 8 women and 8 men, both on an empty stomach (fasting) and after a meal. In this paper, we compared the experimental ethanol concentration with theoretical values calculated by various methods.
An analysis of the obtained results allowed us to state that the best correlation was achieved for the method assuming immediate elimination from the beginning of consumption (used routinely by the authors), and the method assuming an absorption time of 30 minutes and a 10% alcohol deficit (difference between the theoretical and actual ethanol concentration).
Słowa kluczowe
Alcohol; Time of absorption; Alcohol calculations; Prediction of BAC.