Aspiration Pneumonia as a Marker of a High Healthcare Utilisation Trajectory in Older Adults With Dementia: A Retrospective Cohort Study

OBJECTIVES: To determine whether recorded aspiration pneumonia in older adults with dementia was associated with subsequent high inpatient use and to estimate its associations with all-cause mortality, any hospital admission and cumulative length of stay. METHODS: This single-centre retrospective cohort study examined electronic medical records from a single tertiary hospital to identify 500 adults aged 65 years and older with Alzheimer's disease, vascular dementia or mixed dementia. Participants were followed for up to 36 months (median 20 months). Recorded aspiration pneumonia was analysed as an exposure available in the analytic dataset. Multivariable Cox, logistic and negative binomial models were adjusted for age, sex, dementia subtype, baseline dementia severity and baseline Mini-Mental State Examination (MMSE) score. Exact aspiration-event dates and clinically important domains including frailty, functional status, residence before admission, swallowing assessment, oral-health measures, medication burden and comorbidity burden were not available in the dataset. RESULTS: Recorded aspiration pneumonia occurred in 24% of participants. After adjustment, the cohort-level mortality signal remained imprecise (HR 1.65, 95% CI 0.85-3.21). In contrast, aspiration pneumonia was independently associated with higher odds of hospitalisation (OR 2.02, 95% CI 1.29-3.16) and greater cumulative length of stay among those admitted (IRR 1.54, 95% CI 1.17-2.01). CONCLUSIONS: In this dementia-specific cohort, recorded aspiration pneumonia was common and consistently associated with greater subsequent inpatient use. The findings support interpreting recorded aspiration pneumonia as a pragmatic clinical marker of heightened service dependence within a broader frailty and illness context and underscore the value of multidisciplinary review and anticipatory care planning after such events.