Table 1 Description of survey and registry variables* included in the present study

Demographics

Sex

Male vs. female

Age

Age when answering the NorMA survey

Norwegian born

Born in Norway vs. born in other countries

2.5

Family with drug or mental health problems

Growing up in a family with drug use and/or psychiatric disorders vs. no such problems

3.5

Education

Primary school (10 years) or less vs. more than primary school

1.2

In job or education

Working or in an educational program prior to baseline imprisonment vs. not

2.2

Married

Married/cohabitant vs. not

1.1

Benefits as main income

Benefits (pensions, sickness benefits or unemployment benefits) as main income vs. other income

1.8

Homeowner

Owner of private housing vs. not

1.2

Mental Health

HSCL-10

Hopkins symptoms check list, measuring symptoms of psychological distress. Cut-off (> 1.85) indicates psychological distress (Derogatis et al., 1974). Mean-imputation is used if missing on two or less of the 10 questions.

14.1

Substance use

Used alcohol

Ever used alcohol, denoted “lifetime”

1.0

Age at onset, alcohol use

Age at first use of alcohol

Used illegal drugs

Ever used illegal drugs, denoted “lifetime”

2.9

Age at onset, drug use

Age at first use of illegal drugs

Daily use

Substance use (not including alcohol) 4 times per week or more during the 6 months leading up to baseline imprisonment vs. less than 4 times per week

OAT

In opioid agonist treatment at time of survey

6.1

Attended treatment

Ever attended drug and/or alcohol treatment

AUDIT

Alcohol Use Disorders Identification Test – a 10 items screening tool for identification of problematic alcohol use during the year leading up to baseline imprisonment. Cut-off (> 19) indicating dependence and need for treatment

1.9

DUDIT

Drug Use Disorders Identification Test – an 11 items screening tool for identification of problematic use of illegal drugs or prescribed medication during the year leading up to baseline imprisonment. Cut-off (> 24) indicating dependence and need for treatment

3.4

Prescription medicine

Used prescribed medication for sleeping disorders, ADHD, anxiety, depression, OAT or pain during the 6 months leading up to baseline imprisonment and/or during baseline imprisonment vs. not

Data from the Norwegian Death Registry (NCoDR) N = 56

Time of death

Date as stated in the NCoDR

Age

Age at death. Missing for eight deaths in the Death registry, and thus calculated from age at baseline and date of death.

Underlying cause of death

ICD10 code describing the disease or injury that initiated the train of events leading directly to death. Dichotomized into “Internal death” and “External death”.

14.3

Internal cause of death

Underlying cause of death with ICD10 codes in Chaps. 1–17 (A00-Q99), excluding codes related to drug-related deaths as stated below

External cause of death

Underlying cause of death with ICD10 codes in Chap. 20 (V00-Y98), plus drug-related deaths as stated below

Drug-related death

Underlying cause of death with ICD10 codes F (11–12,14–16,19), X (41¹,42²,44², 61¹,62², 64²) and Y (11¹,12²). Included in “External cause of death”.

Data from the Norwegian Prison Registry, on baseline imprisonment N = 733

Security level

Released from high security unit at end of baseline imprisonment

7.6

Duration

Length of baseline imprisonment (in months) from date of imprisonment to date of release or end of follow-up.