Illegal drugs are a major public health concern and a top-ten cause of death and disability in Norway. The problem is hard to manage. Administrative registers identify only the users that have been unable or unwilling to to hide their use, there is only weak and limited data available regarding the effects of different treatment alternatives, and the criminalization of youth drug use continues to be viewed as an important preventive approach despite a lack of evidence documenting the claimed effects.
We aim to move the field forward in three ways by combining new statistical approaches and administrative registers with population coverage and data covering multiple life domains:
1. develop and assess different methods for inferring the size of hidden user populations and how these change over time,
2. compare post-treatment outcomes following different types of treatment for drug problems to assess whether these differ by type of treatment, and
3. assess whether "police enforcement intensity" of drug use crimes predicts long term outcomes of the treated youth cohorts.
Illegal drugs form a top-ten cause of death and disability in Norway, which especially reflects the raised mortality risks of at-risk users of opioids. Data on drug use and harms are scarce, with criminal justice and health system data capturing only those unable or unwilling to hide their use. While a variety of treatment approaches are available within the Norwegian health system, the evidence base for these is often weak, and the same is true for the criminal justice approach that remains a core preventative public health strategy to reduce population harms from drug use.
The project will link a large set of administrative data and employ sophisticated and cutting-edge statistical modelling techniques to address key knowledge gaps in this area. The first goal is to improve our understanding of how drug use problems are distributed across population groups and birth cohorts, and how the prevalence and risks of use (which is typically initiated in youth) changes over the lifespan as a result of death and remission (within and outside of the formal treatment system). Since we only observe a subset of those with drug problems at any age, this requires us to model the "risk of being observed" in ways that allows us to correct for how this varies systematically with age, social background etc.
A second goal is to provide comparative data on how patient outcomes vary across different treatments in use for drug use and dependence, and how such treatment effects interact with support and rehabilitation programs. The focus is on ensuring comparability of estimates, using data on treatment episodes across more than a decade to avoid common small-sample issues.
The final goal is to examine how variation (over time and regions) in the use of different criminal justice tools contributes to reducing serious drug-related harms by preventing use in adolescents, reducing progression to heavy or dependent use, or by helping rehabilitate those with use-related problems.