Persistent Delirium Predicts Greater Mortality

To examine the association between persistent delirium and 1-year mortality in newly admitted post-acute care (PAC) facility patients with delirium who were followed regardless of residence. Observational cohort study. Eight greater-Boston skilled nursing facilities specializing in PAC. Four hundred twelve PAC patients with delirium at admission after an acute hospitalization. Assessments were done at baseline and four follow-up times: 2, 4, 12, and 26 weeks. Delirium, defined using the Confusion Assessment Method, was assessed, as were factors used as covariates in analyses: age, sex, comorbidity, functional status, and dementia. The outcome was 1-year mortality determined according to the National Death Index and corroborated using medical record and proxy telephone interview. Nearly one-third of subjects remained delirious at 6 months. Cumulative 1-year mortality was 39%. Independent of age, sex, comorbidity, functional status, and dementia, subjects with persistent delirium were 2.9 (95% confidence interval=1.9-4.4) times as likely to die during the 1-year follow-up as subjects whose delirium resolved. This association remained strong and significant in groups with and without dementia. Additionally, when delirium resolved, the risk of death diminished thereafter. In patients who were delirious at the time of PAC admission, persistent delirium was a significant independent predictor of 1-year mortality.