Carbohydrate-Deficient Transferrin (CDT), a biomarker for excessive alcohol consumption, has been used in driver’s license regranting programs in the UK and other European countries, but relevant data is lacking in Taiwan. This study collected %CDT data from repeat drunk driving offenders to monitor their alcohol consumption and aims to provide local data to inform policies in Taiwan.

The objective of this study is to assess whether alcohol consumption decreases over a 12-month period, as measured by %CDT values and Alcohol Use Disorders Identification Test - Consumption (AUDIT-C) scores.

Study Design

This study was conducted from 2020 to 2023, involving 65 recidivist drunk drivers whose licenses had been revoked and who sought to reapply. Participants were referred to our hospital for a one-year, monthly evaluation and intervention program. Data were collected on gender, age, marital status, education level, employment status, years of alcohol consumption, primary type of alcohol consumed, DSM-5 severity, AUDIT, and AUDIT-C scores. Blood tests, including GGT, AST, ALT, triglycerides, cholesterol, and %CDT, along with AUDIT-C assessments, were conducted at the 1st, 4th, 7th, and 11th evaluations.

Basic demographic information is shown in Image 1. There was no significant difference in %CDT before and after the intervention (p = 0.332), with values of 1.99% and 2.28%, respectively. Among 42 participants who completed the 12-month intervention, %CDT showed no significant change (p = 0.46; 1.93% vs. 1.83%). For 23 participants who did not complete the intervention, %CDT also showed no significant difference (p = 0.219; 2.11% vs. 3.14%).

However, AUDIT-C scores significantly decreased across all groups. The total group’s scores dropped from 4.51 to 3.20 (p = 0.00091), the completion group from 4.00 to 2.60 (p = 0.011), and the non-completion group from 5.43 to 4.30 (p = 0.025). These results are shown in Image 2, and the correlations between baseline variables are displayed in Image 3.

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Our study found that monitoring drunk-driving recidivists with %CDT every three months did not yield a statistically significant change in %CDT, but did result in a significant reduction in AUDIT-C scores. Fleming et al. (2004) suggest that psychological pressure from long-term biomarker monitoring may have a therapeutic effect, with bimonthly CDT follow-ups potentially beneficial. Thus, using %CDT for license reinstatement is feasible, though adjustments to assessment intervals and inclusion of other biomarkers should be considered.

Fleming et al., Alcohol Clin Exp Res 2004; 28: 1347–55.

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