Elsevier

Injury

Volume 47, Issue 1, January 2016, Pages 226-234
Injury

The influence of dementia on injury-related hospitalisations and outcomes in older adults

https://doi.org/10.1016/j.injury.2015.09.021Get rights and content

Abstract

Introduction

Injury is the most common reason for admission to hospital in people with dementia in Australia. However relatively little is known about the temporal trends and the hospital experience of people with dementia hospitalised for an injury. This population-based data linkage study compared the causes, temporal trends and health outcomes for injury-related hospitalisations in people with and without dementia.

Methods

Hospitalisation and death data for 235,612 individuals aged 65 years and over admitted to hospital for an injury over the ten year period (2003–2012) in New South Wales, Australia were probabilistically linked. Descriptive statistics including chi square tests, observed and age-standardised admission rates and rate ratios (RRs) were calculated. Trends over time were analysed using negative binomial regression.

Results

There were 331,432 injury-related hospitalisations over the study period. Both the observed (RR 3.16; 95% CI 3.13–3.19) and age-standardised admission rate ratios (RR 1.78; 95% CI 1.77–1.79) were higher for people with dementia. Age-standardised rates increased by 3.5% (95% CI 3.1–3.9) per annum over the study period for people without dementia. In contrast, for people with dementia, rates increased by 2.4% (95% CI 1.8–3.1) per annum until 2007 and then decreased by 3.1% (95% CI −4.4 to −1.7) per annum from 2007 onwards. Compared to people without dementia, a higher proportion of people with dementia were hospitalised as a result of a fall (90.9% vs 75.2%, p < 0.0001), sustained a fracture (57.2% vs 52.1%, p < 0.0001), notably hip fracture (30.7% vs 14.7%, p < 0.0001), had longer mean hospital lengths of stay (LOS) (16.5 vs 13.6 days), and higher 30-day mortality (8.7% vs 3.6% p < 0.0001), although this pattern was not consistent across all injury types.

Conclusions

People with dementia are disproportionately represented in injury-related hospitalisations, experience longer hospital LOS and have poorer outcomes. Ninety percent of hospitalisations for people with dementia were as a result of a fall, highlighting the importance of developing and implementing effective fall-related preventive strategies in this high risk population.

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.

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