Mortality Risk among Cocaine Users before and after the Economic Recession: Results of a Longitudinal Study.

Background: Studies have highlighted 2 different groups of cocaine users (CUs): "socially integrated" (stable living conditions, regular employment, use cocaine alone or in combination with other psychoactive substances) and "socially marginalized" (socioeconomic and health problems, former or current heroin users, many injecting cocaine). These differences are also found in the elevated mortality risk for CUs, higher among subjects with cocaine and heroin use. This study targeted residents in Northern Italy who turned to a public treatment center for drug addiction following problems caused by primary cocaine use between 1982 and 2016. Objectives: To estimate mortality risk for subjects who have never used heroin (CUs) compared to that of subjects who have used heroin (HCUs). Method: Retrospective cohort study. We selected 1,993 subjects; 18,015 Person Years (PY). Results: Over time, the quota of subjects injecting cocaine and using heroin decreased, while patients not using heroin increased. Both new patients and crude mortality rates (CMR) decreased during the years 2009-2012 and increased in the following period. CMRs were 5.55 per 1,000 PY, higher for HCUs, men and subjects aged over 44 years. Standardized mortality rates were 3.49, higher for women, injecting cocaine and HCUS. Among CUs, most of the deaths were from injury excluding drug related and tumors; among HCUs, from drug-related causes and diseases of the cardiovascular system. Conclusion: The study results show a change in the characteristics of SERD clients being treated for primary cocaine use, which are reflected both in mortality risk and causes of death. After a long period of a decrease, mortality risk increased in the period after the economic recession. Aspects concerning the effects of the economic recession on the problematic consumption of cocaine and on the risk of death are discussed.