Benzodiazepine Dependence After Cardiothoracic Intensive Care: A Nationwide Cohort Study

This study aimed to describe benzodiazepine use after cardiothoracic intensive care unit (ICU) care, including factors associated with new long-term high-potency benzodiazepine use after critical care, and to determine whether benzodiazepine use is associated with an increased risk of death. A nationwide retrospective cohort study was conducted of all cardiothoracic ICU patients in Sweden between 2010 and 2018. All patients older than 18 years who survived the first 3 months after admission to a cardiothoracic ICU were eligible for inclusion. A total of 36,135 patients were screened, and 4163 were ineligible. In the final study cohort of 31,972 benzodiazepine-naive patients admitted to critical care, 578 patients had persistent high-potency benzodiazepine use. The proportion of new persistent benzodiazepine users was 5% in the first 3 months after ICU care, followed by a decline to a consistent level of 2% at 2 years of follow-up. Factors associated with persistent benzodiazepine use included higher age, female sex, psychiatric and somatic comorbidities, substance abuse, and preadmission opioid and low-potency benzodiazepine use. Adjusted hazard ratio for death 6 to 18 months after admission for new persistent benzodiazepine users was 2.2 (95% CI, 1.5-3.1; P < .001). High-potency benzodiazepine consumption is increased 2 years after admission to cardiothoracic ICU care despite lack of support for long-term use of benzodiazepines. Being older and female, prior opioid use, and comorbid conditions were among risk factors for persistent benzodiazepine use. Persistent benzodiazepine users had an increased risk of death.