Severe COVID-19 cases among patients admitted to treatment for alcohol and drug use disorders in Catalonia

Introduction: Patients admitted to treatment for substance use disorders (SUD) are often exposed to worse health outcomes. The objective of this study is to assess severe cases of COVID-19 among patients admitted to treatment for SUD in Catalonia between 2018 and 2019.

Methods: A total of 26,773 patients were admitted to treatment for SUD in the 63 specialized centres of Catalonia. Population-based registers were assessed including sex, age, country of birth, socioeconomic level, comorbidity index (GMA), the main drug used (alcohol, cocaine, cannabis, or heroin) and COVID-19 PCR tests performed in 2020. COVID-19 patients not admitted to hospitals were considered as not severe cases, while admissions to hospitals, intensive care units (ICU) or deaths were considered as severe, both related with the infection according to the ICD. Logistic regression models were adjusted to assess the risk (Odds Ratio[OR]) of severe COVID-19 outcomes by independent variables.

Results: A total of 601 patients tested positive of COVID-19, the mean age was 49.1 years, 78% were men and 55% of the cases were admitted to alcohol use disorder. Out of the 601 COVID-19 positive patients, 104 (17.3%) were admitted to hospitals, ICU or die during 2020. Compared to COVID-19 positive patients not admitted to hospitals, the risk of severe cases was higher among patients admitted to treatment for alcohol use disorder (OR: 2.37 95% IC 1.19 - 4.75), those born in out of Spain (OR: 2.10, 95% IC 1.25 - 3.52) and those with other comorbidities (higher GMA) (OR: 7.27, 95% IC 2.55 - 20.67).

Conclusions: This is one of the first population-based analysis of the impact of severe cases of COVID-19 on patients admitted to treatment for substance use disorders. Attention and clinical management of severe COVID-19 patients with SUD should be focused on those admitted for alcohol use and those with other comorbidities.