Global Health
Mortality following substance use disorder treatment: population-based record-linkage retrospective cohort design Andrés González-Santa Cruz* Andrés González-Santa Cruz Alvaro
Background. In Chile, the Government funds substance use disorder treatment (SUD) for all individuals with public health insurance (approximately 81% of the population). There is limited information regarding short-term, medium-term, and long-term mortality risks. We described the standardized mortality ratios (SMRs) for all adult patients in publicly funded SUD treatments from 2010-2022.
Methods. We conducted a population-based, retrospective cohort study by merging individual-level records of adults (aged 18-65) enrolled in Chilean publicly funded SUT programs with national mortality data from 2010 to 2022. We calculated SMRs by comparing the observed number of deaths to the expected number within specific age groups (18-29, 30-44, 45-59, and 60-65), periods (annually), and across different sex categories. Stratum-specific population estimates were obtained from the Ministry of Health’s mortality data, supplemented by population projections from the National Institute of Statistics’ open data portal. The 95% confidence intervals (CIs) were calculated using Vandenbroucke’s method.
Results. There were 100,322 people with at least one admission to treatment during 2010 and 2022. Seventy-four percent were male, and the average age at admission was 39 (standard deviation= 10.5). The SMR in the SUT population was 15.5 (95%CI 15.0, 16.1) times higher than expected based on the general population. Women aged between 30-44 had a mortality risk up to 29.6 times (95%CI 26.0, 33.5) higher than expected (See Figure 1).
Conclusions. These descriptive results show a large cumulative mortality risk among people in SUT, compared to the general population, particularly among women, and with the largest sex gap at younger ages. The specific contribution of substance use in explaining this elevated risk and the effect of SUT as a public health strategy to mitigate these disparities will be further explored.
