Injury-related hospitalisation in community-dwelling older people across the cognitive spectrum: A population based study

Objectives: To describe the injury profile, hospitalisation rates and health outcomes for older people with cognitive impairment and to determine whether these differ from those with normal cognition. Methods: Participants were 867 community-dwelling 70-90 year olds enrolled in the population-based longitudinal Sydney Memory and Ageing Study (MAS). Participant's cognitive status was classified as normal, mild cognitive impairment (MCI) and dementia at baseline, then 2, 4 and 6 years' follow-up. MAS records were linked to hospital and death records to identify injury-related hospitalisations for the 2-year period following each assessment. Results: There were 335 injury-related hospitalisations for participants; 222 (25.6%) participants had at least one injury-related hospitalisation. The injury-related hospitalisation rate for participants with MCI (63.0 [95%CI 51.6-74.4] per 1000 person-years) was higher than for people with normal cognition (39.3 [95%CI 32.4-46.1] per 1000 person-years) but lower than people with dementia (137.1 [95%CI 87.2-186.9] per 1000 person-years). Upper limb fractures (22.1%) were the most common injuries for participants with normal cognition, and non-fracture head injuries for participants with MCI and dementia (25.9% and 23.3% respectively). Participants with dementia had a higher proportion of hip fractures (20.0%, p = 0.0483) than participants with normal cognition. There was no difference in 30-day mortality between participants with normal cognition, MCI and dementia (3.9%, 1.7%, 3.3% respectively). Conclusion: Older people with objectively defined MCI are at higher risk of injury-related hospitalisation than their cognitively intact peers, but lower risk than people with dementia. Falls-risk screening and fall prevention initiatives may be indicated for older people with MCI.