A Register-Based Follow-Up Study of Age-Specific Mortality and Causes of Death of Men, Women and Accompanying Children After Substance Use Treatment.

Aim: This long-term follow-up study assessed substance related mortality by sex and compared it with the age-matched general population, with the aim of informing the development of treatment services. Methods: Data included 10,891 former patients who had sought treatment for substance use between 1990 and 2009, and a special group of 1,076 children who had accompanied their parent(s) to family treatment. Treatment data were linked to national register data concerning education, hospitalizations and death by 2019. Age-specific death rates, standardized mortality ratios and causes of death were compared with the Finnish general population. Results: By 2019, a larger proportion of the 7,334 treatment-seeking men (42.6%) than of the 3,557 women (27.4%) had died. The underlying cause of death was alcohol and/or drug related in one-third of the deaths and two-thirds when further causes were included. Age-specific comparisons with the general population revealed that the studied men and women had markedly higher death rates and the difference increased decade by decade, being highest among the youngest age-groups (standardized mortality ratios were 9.8 for men and 13.8 for women born in the 1980s). Out of the 1,076 children, 15 boys (2.8%) and four girls (0.7%) had died, mostly due to substance use or violence related causes. Conclusions: Mortality was significantly increased for several years after treatment highlighting the need for long-term follow-up, as well as after-care and easy re-entry to treatment. Special attention should be paid to the relatively higher increase in mortality risk among women.