Delirium in the elderly is a serious and potentially preventable condition with significant long-term health care costs. A study by Leslie et al. (2008) found that patients who developed delirium during hospitalization had significantly higher health care costs and shorter survival times compared to those without delirium. After adjusting for demographic and clinical factors, the average daily cost for patients with delirium was more than twice that of patients without delirium. Total costs attributable to delirium ranged from $16,303 to $64,421 per patient, implying a national annual burden of $38 billion to $152 billion. The study followed 841 patients aged 70 years and older who had participated in a previous delirium prevention trial. Delirium was diagnosed using the Confusion Assessment Method, and patients were followed for one year after discharge. Data on health care costs were obtained from Medicare administrative files, hospital billing records, and the Connecticut Long-term Care Registry. Total costs were calculated using Medicare reimbursed amounts and adjusted for inflation. Regression models showed that patients with delirium had significantly higher health care costs even after adjusting for relevant factors. The study also found that delirium costs were higher in models that accounted for right-censoring, with costs ranging from $60,516 to $64,421 per patient. Ninety-five percent of the cost difference was due to inpatient and nursing home care. The economic impact of delirium is substantial, comparable to that of falls and diabetes. The study highlights the need for increased efforts to prevent and treat delirium, given its significant clinical and economic implications. Despite limitations, the study underscores the importance of addressing delirium as a serious condition with long-term consequences. Future research should focus on identifying the specific sources of increased health care costs associated with delirium.Delirium in the elderly is a serious and potentially preventable condition with significant long-term health care costs. A study by Leslie et al. (2008) found that patients who developed delirium during hospitalization had significantly higher health care costs and shorter survival times compared to those without delirium. After adjusting for demographic and clinical factors, the average daily cost for patients with delirium was more than twice that of patients without delirium. Total costs attributable to delirium ranged from $16,303 to $64,421 per patient, implying a national annual burden of $38 billion to $152 billion. The study followed 841 patients aged 70 years and older who had participated in a previous delirium prevention trial. Delirium was diagnosed using the Confusion Assessment Method, and patients were followed for one year after discharge. Data on health care costs were obtained from Medicare administrative files, hospital billing records, and the Connecticut Long-term Care Registry. Total costs were calculated using Medicare reimbursed amounts and adjusted for inflation. Regression models showed that patients with delirium had significantly higher health care costs even after adjusting for relevant factors. The study also found that delirium costs were higher in models that accounted for right-censoring, with costs ranging from $60,516 to $64,421 per patient. Ninety-five percent of the cost difference was due to inpatient and nursing home care. The economic impact of delirium is substantial, comparable to that of falls and diabetes. The study highlights the need for increased efforts to prevent and treat delirium, given its significant clinical and economic implications. Despite limitations, the study underscores the importance of addressing delirium as a serious condition with long-term consequences. Future research should focus on identifying the specific sources of increased health care costs associated with delirium.