Driving license regranting: hair EtG, serum CDT, and the role of socio-demographic and medico-legal variables.

Driving under the influence (DUI) of alcohol is a road safety problem. Driving license regranting is based on the evaluation of medico-legal and toxicological variables that may include serum carbohydrate-deficient transferrin (CDT) and hair ethyl glucuronide (hEtG). The aim of the study was to compare the diagnostic performance of CDT and hEtG in a population of DUI-offenders., Other factors potentially associated with heavy alcohol use were explored. The population included DUI-offenders examined during the period of January 1st, 2019, through June 30th, 2022. Socio-demographic, medico-legal, and toxicological variables were collected. CDT in serum and EtG in head hair were determined in all subjects. Excessive alcohol intake (hEtG≥30pg/mg) was considered cause for unfitness to drive. Cohen's kappa coefficient was calculated. Descriptive analyses were performed using chi-square and Mann-Whitney tests. Variables significantly different between the groups were included in a multivariate binary logistic regression model. The sample encompassed 838 subjects (case group: 179, comparison group: 689). CDT exhibited poor agreement (κ=0.053) with hEtG as the reference test. Lower education, age at DUI, heavy smoking, and GGT levels associated with heavy alcohol consumption differentiated the two groups. For DUI-offenders, the use of CDT to assess heavy alcohol consumption is limited, possibly due to the time-window assessed, the time required for normalization and the different amount of ethanol needed to reach higher CDT levels, in comparison to hEtG; thus, hEtG assessment is strongly recommended for this population. Heavy smoking, GGT, education, age could be related to heavy alcohol consumption and higher risk of DUI.