Background: Delirium is a frequent complication associated with hospitalization of older adults leading to serious complications but it is potentially preventable. The overall data regarding admission rates and its impact in Thai geriatrics are limited.
Objective: To identify admission, mortality rates of older persons with delirium and its consequences.
Material and Method: Information on illness of inpatients and casualties came from hospitals nationwide and from hospital withdrawals from the three health insurance schemes in fiscal 2010. The data included 96% of the population. The data were analyzed by age groups in delirious patients.
Results: Delirium occurred in 11,410 of all admissions; contributing admission and mortality rates of 155.4 and 6.4/100,000 older persons. These figures increased with age. The average length of stay in persons with and without delirium were 22.3 and 5.4 days and the average hospital charges were 53,174 and 18,230.8 Baht, respectively.
Conclusion: The admission rate of patients with delirium was lower than prior reports; underdetection and underreport should be considered. Admission and mortality rates rose with age. There was an increase in length of stay and hospital charges.

Keywords: Delirium, Confusion, Confusional state, Clinical epidemiology, Elderly