Comparisons of long-term mortality between alcohol-use-disorder (AUD) and opioid-use-disorder (OUD) groups within clinical cohorts are scarce. This study aimed to do this within one clinical cohort comprising groups suffering various severe substance use disorders. Design: Observational cohort design. Prospective study of mortality 1998–2016, Cox regression. Sample/setting: 464 persons in specialist SUD treatment at start of observation period. Three subgroups defined by SUD characteristics at the beginning of the observation period, were studied: participants with 1) OUD, on opioid agonist treatment (OAT), (OUD/OAT-group), 2) AUD, no other SUDs (AUD-alone group), 3) AUD as part of a poly-substance-use disorder (AUD/PSUD group). Measures/covariates: Comparison of mortality risks and causes of death (somatic diseases/traumatic causes/substance-induced deaths/unknown cause) between OUD/OAT versus AUD-alone, and AUD-alone versus AUD/PSUD groups. Hazard ratio (HR) adjusted for baseline age (1 January 1998), sex, and socioeconomic/SUD characteristics. AUD-alone versus OUD/OAT: Unadjusted mortality risk was higher in the AUD-alone group HR 1.99 (95% CI 1.33–2.99). However, in adjusted analysis type of SUD showed no statistically significant association with increased mortality aHR 0.91 (0.54–1.54), only male sex and increasing baseline age were independently associated with increased mortality risk. Cause-of-death distributions were very similar and somatic diseases caused over 50% of deaths in both groups. AUD-alone versus AUD/PSUD: Unadjusted mortality risk was higher in the AUD-alone group (HR 2.57 (1.65–4.00). However, in adjusted analysis type of SUD showed no statistically significant association with increased mortality aHR 1.40 (0.81–2.44), only male sex, increasing baseline age, and “not being in work or education at study inclusion” were independently associated with increased mortality risk. Substance-induced deaths were most common in the AUD/PSUD group (43%). In adjusted analyses there were no statistically significant differences in mortality risk between the three subgroups. Somatic diseases were the main cause of death. Besides efforts to improve social rehabilitation and to treat the substance use disorders as such, early and targeted lifestyle interventions, and measures for early detection, treatment and follow-up of somatic disorders are essential to reduce mortality in both AUD and OUD populations. Not applicable
Skeie et al. (Wed,) studied this question.