Ethyl glucuronide in hair: A 5-years retrospective cohort study among drivers under the influence of psychoactive substances and alcohol

Abstract

The main aim of the study was to investigate ethyl glucuronide (EtG) hair levels and alcohol consumption behaviour of a large cohort of driving under the influence (DUI) subjects between 2015–2019. Since alcohol is the most widespread psychoactive substance in the world, evaluation of alcohol drinking behaviours can help in preventing alcohol misuse or, at least, limit high-risk situation, such as driving under the influence of ethanol. Ethyl glucuronide in hair is a sensitive and specific biomarker for estimating previous continuative alcohol consumption within a relatively long period, depending on hair length. EtG in hair tests, measured in the period 2015–2019, to all the 18 years old subjects that were resident in the Province of Pavia, were collected and evaluated. The province of Pavia has been divided into three districts, namely the main city together with hinterland (district I), the agricultural flat area (district II) and the rural hilly area (district III). EtG level was defined as ordinal variable, thus dividing data into three groups depending on the drinking behaviour (teetotallers or occasional drinkers, moderate continuative users, and chronic excessive alcohol users). Effects of age, gender and district on alcohol consumption behaviour are investigated with an ordinal logit model. A state sequence analysis was used to study people's alcohol consumption behaviour over time. In total, 22.2% of the drivers provided EtG in hair values. Among positive cases, a prevalence of males (96.3%), aged 35–44 (32.6%), coming from district I (38.2%) was observed. All age classes have a reduced drinking risk if compared to the ≥ 55 years old class: subjects aged 18–24 have 70% (OR≈0.29, P < 0.001) lower risk, 63% (OR≈0.37, P < 0.001) lower risk for the 25–34, half (OR≈0.51, P < 0.001) for the 35–44 and 36% (OR≈0.64, P < 0.001) for the 45–54. A general decreasing trend in EtG values over time was observed for the subjects who have undergone at least 4 repeated EtG measurements ( n = 460). Our study indicates that, compared to 2015, in the last few years the portion of heavy drinkers, among subjects tested for hEtG due to DUI issues, has decreased. When drinking habits were related to age, we observed that overall high-risk increased with increasing age. The characteristics of the territory are also associated with different drinking patterns: in the district mainly devoted to the cultivation of vineyards (district III) there is a 31% higher risk of being a drinker compared to people living in district I. The data obtained from this retrospective observational study suggested that the inclusion of EtG in hair test in the protocol for driving license renewal (DLR) could have contributed to raise awareness among people about the new diagnostic tools available for monitoring alcohol chronic behaviors, thus partially limiting ethanol consumption habits associated with high-risk issues. EtG in hair test in the drive license reissuing protocol appeared to contribute in decreasing alcohol misuse behaviors. Moreover, this study highlighted some potential risk factors related to alcohol drinking habits among drivers such as being male sex, age ≥ 55 years, and coming from rural areas.