Dementia in the acute hospital: prospective cohort study of prevalence and mortality.

Background: Increasing numbers of people will die with dementia, many in the acute hospital. It is often not perceived to be a life-limiting illness.

Aims: To investigate the prevalence of dementia in older people undergoing emergency medical admission and its effect on outcomes.

Method: Longitudinal cohort study of 617 people (aged over 70). The main outcome was mortality risk during admission.

Results: Of the cohort, 42.4% had dementia (only half diagnosed prior to admission). In men aged 70-79, dementia prevalence was 16.4%, rising to 48.8% of those over 90. In women, 29.6% aged 70-79 had dementia, rising to 75.0% aged over 90. Urinary tract infection or pneumonia was the principal cause of admission in 41.3% of the people with dementia. These individuals had markedly higher mortality; 24.0% of those with severe cognitive impairment died during admission (adjusted mortality risk 4.02, 95% CI 2.24-7.36).

Conclusions: The rising prevalence of dementia will have an impact on acute hospitals. Extra resources will be required for intermediate and palliative care and mental health liaison services.