Twelve-month mortality among delirium subtypes.

This study used data from the Delirium Among the Elderly in Rural Long-Term Care Facilities Study and data from the National Death Index (NDI) to examine mortality among 320 individuals. Individuals were grouped into noncases, subsyndromal cases, hypoactive delirium, hyperactive delirium, and mixed delirium on the basis of scoring using the Confusion Assessment Method (CAM), NEECHAM Scale, Mini-Mental State Examination (MMSE), Clinical Assessment of Confusion-A (CAC-A), and Vigilance A instruments. Risk ratios of mortality using "days of survival" did not reach statistical significance (α = .05) for any subgroup. Underlying cause of death (UCD) using International Classification of Disease, 10th version (ICD-10), showed typical UCD among older adults. There appeared to be clinical differences in UCD between delirium subgroups. Findings supported the conclusion that careful monitoring of patients with delirium and subsyndromal delirium is needed to avoid complications and injuries that could increase mortality.