Delirium in elderly home-treated patients: a prospective study with 6-month follow-up.

Delirium usually occurs during hospitalisation. The aims of this study were to evaluate the incidence of delirium in "hospital-at-home" compared to a traditional hospital ward and to assess mortality, hospital readmissions and institutionalisation rates at 6-month follow-up in elderly patients with intermediate/high risk for delirium at baseline according to the criteria of Inouye. We performed a prospective, non-randomised, observational study with 6-month follow-up on 144 subjects aged 75 years and older consecutively admitted to the hospital for an acute illness and followed in a geriatric hospital ward (GHW) or in a geriatric home hospitalisation service (GHHS). Baseline socio-demographic information, clinical data, functional, cognitive, nutritional status, mood, quality of life, and caregiver's stress scores were collected. Of the 144 participants, 14 (9.7%) had delirium during their initial hospitalisation: 4 were treated by GHHS and 10 in a GHW. The incidence of delirium was 16.6% in GHW and 4.7% in GHHS. All delirious patients were very old, with a high risk for delirium at baseline of 60%, according to the criteria of Inouye. In GHW, the onset of delirium occurred significantly earlier and the mean duration of the episode was significantly longer. The severity of delirium tended to be higher in GHW compared to GHHS. At 6-month follow-up, mortality was significantly higher among patients who suffered from an episode of delirium. Moreover, they showed a trend towards a greater institutionalisation rate. GHHS may represent a protective environment for delirium onset in acutely ill elderly patients.