Latent classes of substance use across three age groups and associations with criminality and use of healthcare services – a record linkage study

Background: Consequences of substance use depend, not only on the volume of consumption, but also on patterns of use. Yet, little research on community population samples has examined differential patterns of licit and illicit substance use that can inform prevention and treatment efforts in different developmental stages. This study identifies distinct patterns of substance use across three age groups and compares classes on risk of criminal convictions and use of health care services. Methods: Data from a large Danish survey (n=8837) was used to identify patterns of use among adolescents (15 to 18 years), emerging adults (19 to 30 years), and adults (31 to 65 years). The survey data were linked with Danish health registry data and multivariate Cox regressions were performed to examine associations between substance use class memberships, criminal convictions and use of substance-related healthcare services. Results: Across the three age groups, latent class analyses revealed three substance use classes: a low use class, a recent binge drinking and lifetime cannabis use class, and a polysubstance use class. Across age groups, polysubstance use was associated with a markedly higher risk of criminal convictions and use of health care services. For adolescents and adults, the “recent binge drinking and lifetime use of cannabis” class, was also associated with a higher risk for criminal convictions. Conclusions: The present research provides insight into longitudinal outcomes of substance use patterns by using a large population sample and register-based data linkage. Although similarities in substance use across age groups were identified, the study also showed important differences in use that could be used to guide future interventions aimed at different age groups.