The data included 200 OMT patients from southeastern Norway with up to 19 years of follow-up.
The patients were on average 37 years old at their first treatment, about 1/3 were women and they had spent an average of 11 years in OMT.
The crude mortality rate (CMR) was 1.6 deaths per 100 patient years (1.6% per year) for those in treatment, and similarly mortality while off OMT was 3.6% per year.
For OMT patients (under treatment) mortality was dominated by somatic diseases (58%), while 21% of deaths in OMT were categorized as overdoses. Outside OMT, overdoses dominated as the cause of death (50%), while 38% were deaths from somatic causes.
The study shows the importance of long-term treatment in OMT to reduce overdose deaths. In addition, in an aging OMT patient population, health promotion and measures that can prevent somatic illness and death must be a priority.