The non-linear effect of age of first tobacco use on average HONC score can be described as a slight decrease until age 8, followed by a slight increase between 8 and 12 years, and then a sharp decrease with age. Hazardous substance use in adolescence can increase risk for substance use disorders in adulthood, which remain a major public health issue in the United States. So, it is essential to develop new tools for identifying adolescents at risk of developing hazardous substance use among co-users in order to possibly increase the impact of prevention and intervention programs. This study took a preliminary step by determining risk factors associated with hazardous use of alcohol, cannabis, and tobacco — the three of the most commonly used substances by adolescents — and employing them to build joint models for predicting risk of hazardous substance use. To our knowledge,mobile vertical rack this is the first study that attempted to jointly model hazardous use of multiple substances by adolescents specifically for the purpose of quantitative risk prediction.
With information about salient combinations of individual, family and socio-demographic factors, the proposed model can be used to predict scores on quantitative measures of hazardous use for an adolescent user of alcohol, cannabis, and tobacco. A predicted score can be compared with its distribution to assess the relative level of risk for the user. An important novelty of this work is the application of relatively new statistical and machine learning methods for analyzing multiple outcomes. To the best of our knowledge, these methods have not been used so far in the substance use literature. They are better suited for risk prediction than the classical multivariate regression because one allows outcome-specific predictors, thereby providing flexibility for joint modeling that may lead to higher predictive accuracy; and the other allows regularization of regression coefficients to protect against over fitting, thereby helping the model to generalize well on future unseen data. For comparison, we also fitted the classical multivariate regression model, whose results are in Supplementary Table 3.
This model identified a total of ten risk factors, all of which were also identified by MCGLM, but the latter additionally identified family history of hazardous alcohol use and had higher predictive accuracy. None of the individual models identified age of first cannabis use, age of first use of other substances, and family history of hazardous alcohol use, which were identified by MCGLM. Of these, the age of first cannabis use, an important risk factor as per the literature, was identified by MCGLM to be associated with both CPQ-A and HONC scores. Although the individual models identified guardian, parental monitoring, and parental past substance use, which were not identified by MCGLM, the effects of these variables could have been captured partially by similar variables included in the joint model, e.g., vertical grow rack parental attachment and family history variables. One of our key findings is that early age of onset of tobacco use is associated with hazardous use of all three substances. In line with previous literature, one study found that, among adolescent drinkers, past-year smokers were at a higher risk for alcohol use disorders than non-smokers .
Another study evaluating the association between e-cigarette use and the use of other substances showed that early onset of e-cigarette use was associated with increased use of alcohol and cannabis.Another key finding is that lower levels of parental attachment are associated with higher scores of hazardous cannabis and tobacco use. Lower levels of parental monitoring and attachment are also known to be associated with adolescent substance use disorders . Other findings in this study are also generally consistent with the literature. For example, increased age is associated with higher RAPI and HONC scores. Indeed, there is a higher percentage of young adults with alcohol use disorders compared to adolescents, and cigarette use tends to increase with age . The observed reduction in CPQ-A scores with an increase in maternal education is supported by literature showing lower socio-economic status is associated with hazardous substance use . The finding that increased CPQ-A and HONC scores are associated with greater early life stress is also consistent with literature demonstrating that various forms of early life stress such as physical and/or sexual abuse, negligence, parental divorce, and domestic violence tend to increase hazardous use of alcohol, cannabis, and tobacco . Our result indicating that family cigarette use is associated with higher HONC scores is consistent with other studies reporting on the association between family smoking habits and increased adolescent smoking .