​The main aim of the nPRIS-study is to evaluate the access to, and outcomes of, substance use treatment in Norwegian prisons. The data material available in nPRIS is a cohort comprising all persons released from prison during the years 2000 until 2017. The cohort includes more than 150 000 releases of more than 95 000 persons.

In 2017, a similar cohort was linked to the National Cause of Death registry, resulting in a paper regarding overdose deaths after release. The paper, published in the highly respected journal Addiction, received much attention. During the project period, the cohort will be linked to several registries and databases.


We aim to link the following registries in the PriSUD-project:


The Norwegian Prison Registry: The national prison registries includes a range of personal data on people imprisoned in Norway, including age, gender, convictions and sentences, and the actual time spent in prison. The registries also include information on participation in correctional interventions.


The Norwegian Cause of Death Registry: The register includes information on the cause of death based on the International Classification of Diseases version 10 (ICD-10). The registry includes all residents of the country at the time of death. The registry is based on death certificates and information that is coded at a national level.


The Norwegian Prescription Database: The prescription databases contain information on all prescription drugs, whether reimbursed or not, dispensed by pharmacies to individual patients. Prescribers use either the ICD 10 or the International Classification of Primary Care Codes (ICPC) as the code of reimbursement on the prescriptions.


The Norwegian Police Registry: The police registries include information on all registered criminal cases including identified offenders, and provide data on several prosecuting decisions: formal charge leading to conviction, formal charge leading to acquittal, fines and other.


The Norwegian Patient Registry (NPR): The patient registries include information on all patients receiving hospital-level care in both inpatient and outpatient facilities, and acute and emergency services for mental and somatic illnesses. The NPR also include birth date and county of residence, date of admission, date of discharge, and primary and secondary diagnoses according to the ICD-10.


Social welfare data from Statistics Norway: Socio-economic data include information on employment, income and social benefits and are very comprehensive by international standards.