Mortality risk in alcoholic patients in Northern Italy: Comorbidity and treatment retention effects in a 30-year follow-up study

Abstract

Aims: To analyse the general and cause-specific mortality over the course of 30 years among subjects treated for alcohol use disorders (AUD) in Northern Italy. Methods: Cohort of 2499 subjects followed-up for mortality until 31 December 2012. Standardized mortality ratios (SMRs) and 95% confidence intervals (CI) were computed to compare the mortality in the cohort with the general population. Cox regression was used to study the effect of psychiatric disorders, burden of physical comorbidity and retention in treatment on mortality, controlling for socio-demographic factors. Results: During the follow-up, 435 deaths occurred. Compared with the general population, alcoholics experienced a 5-fold increased mortality (SMR: 5.53; 95% CI: 5.03, 6.07). Significant excess mortalitywas observed for a range of specific causes: infections, cancers, cardiovascular, respiratory and digestive system diseases as well as violent causes. In multivariate analysis, the hazard of dying was lower for female gender (hazard ratio [HR]: 0.62; 95% CI: 0.46, 0.84) and for increasing length of retention in treatment (HR for third tertile vs first tertile: 0.43; 95% CI: 0.32, 0.57). Burden of physical comorbiditywas associated with increased hazard of dying (HR for 3+ comorbidities vs no comorbidities: 4.40; 95% CI: 2.91, 6.66). Psychiatric comorbidity was not associated with mortality. Conclusions: Despite the harmful effect of AUD, retention in treatment represented a protective factor against death, suggesting that strategies supporting primary medical- and social-caremay effectively reduce premature mortality.