The evidence for introducing case-finding for delirium and dementia in older medical inpatients in a New Zealand hospital

Objective The aim of this project was to make the case to the managers of a large urban teaching hospital in New Zealand for the introduction of systematic case-finding for pre-existing cognitive impairment/dementia in older hospital inpatients that screen positive for delirium. Method Two hundred consecutive acute admissions aged 75+ in four medical wards were assessed using the 4AT assessment tool for delirium and the Alzheimer Questionnaire (AQ) for pre-existing cognitive impairment/dementia. Length of stay and mortality at 1 year were also collected. Results Over a third of the sample screened positive for delirium and nearly two-thirds of these also screened positive for dementia. The median length of stay was 5 days for delirium without dementia and 7 days for delirium with dementia, compared to 3 days for those who screened negative for both. After adjustment for age, gender and ethnic group, people who screened positive for delirium (with or without dementia) had 50% longer length of stay (p < 0.05) and at least double the risk of death (p < 0.05). Conclusion Older hospital inpatients that screen positive for delirium and dementia using 4AT and AQ have longer lengths of stay and higher mortality. Identification may lead to more timely interventions that help to improve health outcomes and reduce hospital costs.