The 6 and 12 month outcomes of older medical inpatients who recover from delirium.

Objective: To compare the 6 and 12 month outcomes of patients who recovered from delirium by 8 weeks with those who did not have an index episode.

Methods: Older medical inpatients were assessed for delirium using the Confusion Assessment Method. All patients with delirium and a sample of patients without delirium were enrolled. Recovery from delirium at 8 weeks was determined using the Delirium Index and an algorithm based on DSM-III-R criteria. The primary composite outcome was cognitive or functional decline, institutional residence or death at 6 and 12 months. We fitted two logistic regression models to predict outcome odds ratio (OR) of delirium-recovered vs no delirium groups, adjusting for co-morbidity, severity of physical illness and demographic variables. In secondary analyses, we examined each component of the primary outcome separately.

Results: Of 361 patients enrolled, 59 died, 33 withdrew and one was lost to follow-up before 8 weeks. Of 268 patients assessed at 8 weeks, 115 and 95 were in delirium-recovered and no delirium groups, respectively. The 6 month OR for the primary composite outcome was 0.89 (95% CI 0.46, 1.70); the 12 month OR was 1.5 (95% CI 0.77, 2.90). Secondary analyses revealed a clinically important increase in mortality at 6 and 12 months.

Conclusion: Among patients who survived, there were no significant differences in cognition, function or institutional status between delirium-recovered and no delirium groups at 6 and 12 months. If replicated, these findings have potentially important implications for clinical practice and research.