The evaluation of frequency and predictors of delirium and its short-term and long-term outcomes in hospitalized older adults'

Background: Delirium is a common complication in hospitalized older adults with multifactorial etiology and poor health outcomes.

Aim: To determine the frequency and predictors of delirium and its short-term and long-term outcomes in hospitalized older adults.

Methods: A prospective observational study was performed in patients aged ≥60 years consecutively admitted to geriatric ward. Potential risk factors were assessed within 24 hours of hospital admission. Delirium screening was performed on admission and daily thereafter throughout the hospital stay using Confusion Assessment Method (CAM). Patients were followed up at 1-year post-discharge.

Results: The study included 200 patients with mean age 73.1 ± 8.83 years. Incidence and prevalence rate of delirium were 5% and 20% respectively. Multivariable regression analysis revealed emergency admission (OR= 5.12 (1.94-13.57), p=0.001), functional dependency (Katz index of Independence in Activities of Daily Living (Katz-ADL) score <5) 2 weeks before admission (OR= 3.08 (1.30-7.33), p=0.011) and more psychopathological symptoms (higher Brief Psychiatric Rating Scale (BPRS) total score) (OR=1.12 (1.06-1.18), p=0.001) to be independently associated with delirium. Patients in delirium group had significantly high in-hospital mortality (OR= 5.02 (2.12-11.8), p=0.001) and post-discharge mortality (HR= 2.02 (1.13-3.61), p=0.017) and functional dependency (Katz-ADL score <5) (OR= 5.45 (1.49-19.31), p=0.01) at 1-year follow up.

Conclusion: Delirium is quite frequent in geriatric inpatients and is associated with high in-hospital and post-discharge mortality risk and long-term functional dependency. Emergency admission, pre-hospitalization functional dependency, and more general psychopathological symptoms are independently associated factors. Hence, earliest identification and treatment with early implementation of rehabilitation services is warranted.