Different functional outcomes in patients with delirium and subsyndromal delirium one month after hospital discharge.

Background: Subsyndromal delirium has an increasing relevance in the medical literature. There are only three studies in hospitalized elderly patients. Our goal is to demonstrate the importance of this syndrome in a population with more complexity and cognitive impairment than in previous studies.

Methods: Prospective multicentre study in three tertiary hospitals. The health outcomes recorded in the follow-up at 1 month were the persistence of delirium, hospital readmission, discharge destination, death, Barthel index and the Delirium Rating Scale Revised 98. To assess the impact of delirium in the Barthel index at 30 days, we adjusted univariate and multivariate linear regression models.

Results: 85 patients were enrolled; 75.3% of the patients had at least 1 positive item in the Confusion Assessment Method; 45 patients (53%) were diagnosed with delirium and 19 (22.3%) with subsyndromal delirium (SSD). The 30-day risk of death was associated with lower levels of albumin (p = 0.021) and the Cumulative Illness Rating Scale in Geriatrics (CIRS-G; p = 0.003). Adjusting for CIRS-G and the initial Barthel index, the diagnosis of delirium appears to be related to a lower Barthel index at 30 days (p = 0.019), showing a significant linear gradient (p < 0.005).

Conclusion: SSD could help get more accurate diagnoses as well as improve patient management.