Association between the presence of delirium during intensive care unit admission and cognitive impairment or psychiatric problems: the Korean ICU National Data Study

Delirium in the intensive care unit (ICU) may be a preventable risk factor for cognitive impairment or psychiatric problems. We aimed to evaluate the association between the presence of delirium during hospitalization involving ICU care and post-discharge cognitive impairment or psychiatric problems. A retrospective cohort study. A database of nationwide insurance claims data. All adult patients aged 18 years or older who were admitted to an ICU between January 1, 2008, and May 31, 2015, and had no history of previous cognitive impairment or psychiatric problems were included in the study. None. Of 306,011 patients who met the inclusion criteria, the proportion of those who experienced delirium during hospitalization was 55.0% (n = 168,190). The patients with delirium during hospitalization had significantly increased odds for cognitive impairment (adjusted hazard ratio [HR] 1.17; 95% confidence interval [CI] 1.05-1.29) and psychiatric problems (adjusted HR 1.78; 95% CI 1.67-1.90) after discharge compared with patients without delirium. In patients who had delirium, the incidence of cognitive impairment was 210.8 per 1000 person-years. In 19,496 patients who were diagnosed with cognitive impairment, depression (n = 3233, 16.5%), sleep disorder (n = 1791, 9.2%), and anxiety (n = 1683, 8.6%) were commonly co-diagnosed. The most common psychiatric problem was sleep disorder (148.7 per 1000 person-years), followed by depression (133.3 per 1000 person-years). Among patients received ICU care, those who experienced delirium during hospitalization had an increased risk of developing cognitive impairment or psychiatric problems post-discharge. Many patients showed multiple cognitive impairment and psychiatric problems during the follow-up period. Efforts to decrease these problems should be made to increase the quality of life of these ICU survivors.