Persistent Delirium Associated With Poor Outcomes Persistent Delirium Predicts Greater Mortality

Background: Delirium is a geriatric syndrome characterized by acute decline in memory and attention. It is known that hospitalized patients with delirium have higher rates of mortality, morbidity, and loss of independence. The cost of delirium is $100 billion per year. Patients admitted to post-acute care (PAC) with delirium have higher mortality than those with no delirium. This study was limited by assessing delirium only 1 time. It is not known what the effect of persistent delirium is on mortality in this subset of patients. Objective: To study the association between persistent delirium and mortality in a cohort of patients admitted to a PAC. Participants/Methods: Participants were drawn from a previous trial of a delirium abatement program (DAP) involving 8 nursing facilities in the Boston area. This program did not demonstrate any benefit for patients with delirium. For this study, participants were drawn from the control arm of the study. Mortality information was obtained from the National Death Index (NDI). Tests done included the Mini-Mental State Exam (MMSE), Digit Span, Delirium Symptom Interview, and Confusion Assessment Method at baseline 2, 4, 12, and 26 weeks. Results: 412 subjects were included in the trial. Average age was 84 years, 65% were women, and MMSE score was 12.5. Of patients, 38% had dementia. One-year mortality was 39%. Delirium prevalence in survivors decreased over time: 100% at baseline, 67% at 2 weeks, 56% at 4 weeks, 40% at 12 weeks, and 32% at 26 weeks. At 6 months, one third of patients had delirium. Participants with delirium were 3 times more likely to die during the study period (1 year) as compared to those with no delirium. This association persisted when adjusted for other factors and remained strong in participants with and without dementia. The risk of death decreased with resolution of delirium. Conclusions: Delirious patients admitted to PAC have higher mortality rates if they have persistent delirium over 1 year. Reviewer's Comments: Delirium is an important marker of poor outcomes. Health care workers should be vigilant in recognizing patients with delirium and developing protocols to improve care. (Reviewer-Ariba Khan, MD).