My colleague, Torbjorn Skardhamar, and I recently carried out a study on the relationship between alcohol- and drug-related criminality on the one hand, and mortality on the other. We found that people with drug-related criminal records in Norway have a mortality rate that can be up to 15-16 times higher than people with no criminal record. We also found that people with a police record of driving under the influence of alcohol have significantly shortened life-spans compared to the overall population.
These results are somewhat surprising given that Norway is well-known for its egalitarianism. But in fact, the mortality rate for criminal offenders in Norway was as high or higher than in many other European countries, as well as the United States. Our results suggest that, under the surface of Norway’s egalitarian society, stark inequality still exists.
How much of the difference was linked to drug abuse? Previous research has shown that people with criminal records are more likely to have had substance abuse problems, and drug and alcohol abuse is associated with higher mortality rates. However, previous studies of criminal records and mortality have not distinguished between drug use and other lifestyle risks that explain mortality rates.
Our study confirms that drug and alcohol use play an important role in the higher mortality rates observed among convicted criminals: people imprisoned once for use or possession of drugs had a relative mortality risk 8 times higher than those with no criminal record, and those imprisoned more than twice for drug-related offenses had a relative mortality risk of 10 to 13 times higher than those with no criminal record. The differences were higher for women.
We also found that even for prisoners who did not have substance abuse problems, the mortality rate was still nearly twice as high compared to the non-offender population.
Our study is the first nationwide study of criminal records and mortality in Norway, and one of the largest such studies to date worldwide, as it contains the whole population and all offenses that have taken place. It relied on data on crimes, drug, and alcohol use, and mortality from national administrative registries in Norway, and adjusted for age and socio-economic factors.
Mortality rates by the numbers
Relative mortality rate measures how much more likely a person is to die than people in the control group. The new study shows that specific types of crimes are linked to much higher mortality rates than others. The numbers below show the relative mortality rate of groups of people with a criminal record compared to people who have no criminal record:
1.7: Criminal record, but never imprisoned
2: Criminal record
6: Imprisoned for motor vehicle use under influence
9: Imprisoned once for use of drugs
12: Imprisoned more than once for use or possession of drugs.
3: Criminal record, but never imprisoned
2: Criminal record
8: Imprisoned for motor vehicle use under influence
11: Imprisoned once for use of drugs
15: Imprisoned more than once for use or possession of drugs.
Torborn Skardhamar and Vegard Skirbekk. 2013. Relative mortality among criminals in Norway and the relation to drug and alcohol related offenses. PLOS ONE, 9 November 2013. Open Access