The influence of dementia on injury-related hospitalisations and outcomes in older adults
Introduction
Dementia is associated with substantial morbidity and poorer health outcomes, including an increased risk of mortality [1], [2], [3]. People with dementia have three times higher hospitalisation rates and experience hospital lengths of stay almost twice as long as cognitively intact people of similar age [4], [5], [6]. This increased use of hospital services has a significant impact on individuals with dementia and their family and carers, as well as placing a substantial burden on the health care system. In Australia, around 9% of the population aged sixty-five years and over are estimated to have dementia, and this proportion is expected to increase with the ageing of the population [7]. Within Australia's most populous state, New South Wales (NSW), the cost of hospital care for people with dementia was estimated to be $462.9 million in 2006–07, of which $162.5 million was directly attributable to the impact of dementia [8].
Injury has recently been shown to be the most common reason for admission to hospital for people with dementia [4]. However, despite its evident human, clinical and economic impact, relatively little is known about the hospitalisation experience for people with dementia who have sustained an injury. A recent population-based study estimated that people with dementia are more than twice as likely to be admitted to hospital with a hip fracture or head injury as people without dementia [6]. Mortality rates following both hip fracture [9] and head injury [10] are known to be higher in people with dementia, and clinical studies suggest that falls are the most common cause of hospitalisation in people with dementia [11]. No previous research has examined all injury-related hospitalisations by mechanism of injury to determine whether people with dementia have a different injury profile compared to individuals without dementia, nor whether health outcomes of individuals with dementia are worse for all types of injuries.
In addition, trends in injury-related hospitalisations in older people have changed over the past decade. Rates of hospitalisation for hip fractures have declined in Australia [12] and elsewhere [13], [14], [15] whilst hospitalisation rates for injury to the head [16], including traumatic brain injury (TBI) [17], have increased in Australia, mirroring international trends [18], [19]. It is unclear what contribution the increase in prevalence of dementia is having on these observed trends. To address this gap in the evidence-base and to inform planning of care of individuals with dementia, the causes, temporal trends, and health outcomes were compared for older people with and without dementia hospitalised for an injury.
Section snippets
Study population and data sources
NSW is Australia's largest state with an estimated 7.4 million people, 15.1% of whom are aged 65 years and over [20]. The study cohort comprised 235,612 NSW residents aged 65 years and over admitted to a hospital in NSW with an injury for a ten year period 2003–2012.
Two data sets, the NSW Admitted Patient Data Collection (APDC) and the NSW Register of Births, Deaths and Marriages (RBDM) were linked for use in this study. The APDC is an administrative dataset which records hospital admissions
Demographic characteristics
There were 331,432 injury-related hospitalisations for people aged 65 years and older for the ten year study period, two-thirds (65.6%) of whom were female. Overall, 17.5% of injury-related hospitalisations had an additional diagnosis code of dementia, increasing with age from 2.6% for people aged 65–69 years to 29.5% for people aged 95 and over. Both the sex and age distribution for injury-related hospitalisations differed between those with and those without dementia; with a higher proportion
Discussion
This study highlights that people with dementia are disproportionately represented in injury-related hospitalisations with observed hospitalisation rates three times higher than for those without dementia, and age-standardised rates almost double. This increased use of hospital services is consistent with previous reports for all cause admissions [4].
In this cohort, the number of injury-related hospitalisations increased by 5.2% per annum over the study period and age-standardised rates
Conclusion
This study highlights that people with dementia are disproportionately represented in injury-related hospitalisations, experience longer hospital LOS and generally poorer outcomes. The resultant impact both to the individual and to the health system is substantial. Given that ninety percent of hospitalisations were as a result of a fall, development and implementation of effective preventative strategies to prevent falls in people with dementia are urgently needed. It also found that rates of
Conflict of interest statement
There were no conflicts of interest.
Acknowledgements
This study was funded by the Dementia Collaborative Research Centres-Assessment and Better Care, University of New South Wales. The authors would like to thank the NSW Ministry of Health and the NSW Registry of Birth Deaths and Marriages for the provision of the hospitalisation and death data extracts, and the Centre for Health Record Linkage (CHeReL) for the provision of the unique patient identifiers used to link the datasets.
References (35)
- et al.
Fall-related hip fracture hospitalisations and the prevalence of dementia within older people in New South Wales, Australia: an analysis of linked data
Injury
(2013) - et al.
Mortality after discharge from acute care hospitalization with traumatic brain injury: a population-based study
Arch Phys Med Rehabil
(2010) - et al.
Traumatic brain injury in older adults: characteristics, causes and consequences
Injury
(2012) - et al.
Alarming rise in fall-induced severe head injuries among elderly people
Injury
(2007) - et al.
The ICD-10 Charlson Comorbidity Index predicted mortality but not resource utilization following hip fracture
J Clin Epidemiol
(2015) - et al.
Length of comorbidity lookback period affected regression model performance of administrative health data
J Clin Epidemiol
(2006) - et al.
Survival times in people with dementia: analysis from population based cohort study with 14 year follow-up
BMJ
(2008) - et al.
Survival among patients with dementia from a large multi-ethnic population
Alzheimer Dis Assoc Dis
(2005) - et al.
Dementia cognitive impairment and mortality in persons aged 65 and over living in the community: a systematic review of the literature
Int J Geriatr Psychiatry
(2001) People with dementia in hospitals in New South Wales 2006–07. Bulletin no. 110. Cat.no. AUS 165
(2012)