Are biomarkers of chronic alcohol misuse useful in the assessment of DWI recidivism status?

UNLABELLED: A first driving while impaired by alcohol (DWI) conviction is a key opportunity to identify offenders who are at high risk for recidivism. Detection of alcohol use disorder (AUD) is a major target of current DWI assessments. However, offenders frequently underreport their alcohol consumption, and use of biomarkers has been proposed as a more objective indicator. Among the best established are aspartate aminotranferase (AST), alanine aminotransferase (ALT), gamma-glutamyl transferase (GGT), mean corpuscular red blood cell volume (MCV), carbohydrate-deficient transferrin (CDT), and thiamine. To our knowledge, no research has directly verified whether AUD biomarkers predict DWI recidivism status. Using a cross-sectional design, this study tested three hypotheses related to the utility of biomarkers in DWI assessment.

HYPOTHESES: (1) DWI recidivists possess biomarkers indicative of greater prevalence of AUD compared to first-time offenders; (2) multiple biomarkers better differentiate first-time offenders from recidivists compared to individual biomarkers; and (3) biomarkers add significantly to the prediction of recidivism over and above psychosocial questionnaires.

METHODS: First-time offenders (n = 49) and recidivists (n = 95) participated in the study. In addition to self-reported information on sociodemographic and driving characteristics, data from several AUD questionnaires were gathered: Michigan Alcoholism Screening Test, Alcohol Use Disorders Identification Test, Composite International Diagnostic Interview, and Timeline Follow-Back. Blood samples were collected to measure AST, ALT, GGT, MCV, CDT, and thiamine.

RESULTS: AUD biomarkers, taken individually or in combination, did not indicate that recidivists had more frequent AUD compared to first-time offenders. Also, they failed to significantly differentiate first-time offenders from recidivists or predict recidivism status. Finally, the superiority of biomarkers over psychosocial AUD questionnaires was not supported in the laboratory setting.

CONCLUSION: The present findings suggest that biomarkers of chronic patterns of heavy drinking may not be adequate to capture the multiple processes that appear to promote recidivism (e.g., binge drinking, other risky behavioural and personality features). Despite their objectivity, caution is warranted in the interpretation of a positive score on these biomarkers in DWI assessment. Longitudinal research is needed to more comprehensively explore the relationship between positive biomarkers in first-time offenders and their risk of becoming recidivists.