Impact of the Charlson Comorbidity Index on Delirium Outcomes

Introduction Delirium is a significant inpatient healthcare challenge and has a greater incidence among older adults with adverse healthcare outcomes. Yet there are limited established models for risk stratification. The objective is to determine the effectiveness of implementing the Charlson comorbidity index (CCI) score, which is calculated based on the assigned weight for various disease conditions, and to analyze the healthcare outcomes in older hospitalized adults with delirium. Methodology A retrospective cohort study of 214 elderly hospitalized patients between January 1, 2015, and December 31, 2016, with the diagnosis of delirium, was analyzed by grouping based on the severity of diseases as defined in CCI. The primary analysis outcome was to analyze all-cause inpatient mortality, length of hospital stay (in days), 30-day readmissions, and discharge destination in patients with delirium based on CCI scores using regression analysis and nonparametric tests. Secondary analysis included the prevalence and characteristics of delirium patients in different severity levels of CCI. Results Patients with the severe CCI category (with a total score of five and above) spent 10 days longer in the hospital than those who were categorized with mild delirium (p = 0.011). There is a strong association between in-hospital mortality and the severe CCI category (odds ratio (OR), 4.566; 95% CI, 1.17- 1.86 (p = 0.035)). Also, patients with severe CCI scores were 4.6 times more likely to die during hospitalization compared to patients with less severe comorbidities. There were no significant differences found for discharge destination (OR, 0.702; 95% CI, 371- 1.328 (p = 0.277)) and readmission risk (OR, 1.660; 95% CI, 0.664- 4.149 (p = 0.278)) among different CCI groups.  Conclusions Length of stay and inpatient mortality were significantly higher among the severe CCI category compared to the mild category. Our study suggests that CCI can help clinicians, patients, and their families in prognostication and better understanding of goals of care conversations.