Objective: Our scoping review identified the need for research on undiagnosed dementia in residential aged care facilities (RACFs). This study aimed to identify the prevalence of undiagnosed dementia among residents and its associated factors and impact on health outcomes at 12 months.
Methods: A sub-study of the Frailty In Residential Sector over Time (FIRST) study included 553 residents from twelve RACFs of one aged care organisation in South Australia. Baseline (health, demographic, and facility) and 12-month follow-up data (mortality, number of emergency department (ED) presentations and hospitalisation following the first presentation) were evaluated. Undiagnosed dementia was identified when the Dementia Severity Rating Score (DSRS) was >12 and dementia was absent in the medical records. Multivariate analysis was performed to identify associated factors. Health outcomes at 12 months between individuals with and without undiagnosed dementia were examined through regression analyses.
Results: One in four residents had undiagnosed dementia. For each unit increase in the DSRS score, residents experienced 7.3% lower odds of having undiagnosed dementia. Those with a history of delirium, along with those receiving treatment for dementia, had odds of being undiagnosed that were 58.4% and 59.4% lower, respectively. No differences were noted in health outcomes related to mortality, ED presentations, and hospitalisation following the first ED presentation between residents with and without undiagnosed dementia.
Conclusion: Similar to findings in community, undiagnosed dementia is prevalent and becomes less likely as dementia severity increases or with a history of delirium. This does not negatively affect the health outcomes investigated.