This study found several factors for identifying older patients admitted following trauma who are at increased risk of longer LOS as well as functional decline and mortality. Firstly, those admitted with trauma from a low fall are both common (64% of admissions) and experience 26% longer LOS compared to those with higher impact trauma. This group are also 66% more likely to experience functional decline and have increased risk of mortality although this did not reach statistical significance (OR = 1.67, p = 0.205). Secondly, there were high rates of complications in this population, and these were associated with poorer outcomes. Delirium, inpatient fall, pneumonia, VTE, blood transfusions and unplanned ICU admissions were all associated with increased LOS (of between 28% and 52%), with delirium having more than four times increased odds and blood transfusion more than three times odds of functional decline. Delirium and blood transfusions were also associated with a 2.8- and 3.38-times risk of mortality respectively and pneumonia was associated with 4.55 times risk. This risk is beyond that of unmodifiable factors after controlling for confounders including age, admitting unit, premorbid living arrangement, polypharmacy, comorbidities, dementia diagnosis and surgery.
The median acute LOS for this cohort was seven days, in line with published Australian data [2, 16] and in studies of geriatric trauma admissions with geriatric consultation models which have reported LOS of 3–19 days, with most reporting LOS of around seven days [8]. Length of stay is influenced by many factors, however may be improved with system and process changes [17].
It is already established that falls are the major cause of trauma related admissions, and this study is in keeping with previous published data [18]. This likely represents underlying frailty of this group, with increased risk of serious injury including fractures with minimal trauma and decreased physical and functional reserve in the face of trauma resulting in admission to hospital.
Current trauma guidelines do not identify low fall as a triage criterion triggering trauma team response and review. Trauma triage criteria are designed to identify patients presenting with trauma with high risk of significant injury for urgent, coordinated response, starting in the pre-hospital setting, through emergency departments and onto relevant trauma team care. Trauma team care has been shown to improve outcomes in patients presenting with trauma, including in the older population [19, 20]. However, it has been well recognised, that adult triage criteria under triage older patients who are at risk of significant injury despite their apparent low impact mechanism and initial clinical presentation, including “normal” vital signs [21,22,23,24]. Some researchers have argued for the inclusion of low falls as part of geriatric trauma triage tools [25,26,27], however it is recognised that this reduces specificity of these triage tools and risks overwhelming trauma teams and centres due to the prevalence of low falls in the community. There is ongoing debate on how best to triage older persons with trauma and this study highlights those at high risk including those with low falls.
Although our institution is a major trauma centre with an established trauma unit, not all older persons admitted with trauma are admitted under the trauma team. In this study, 21% of older patients presenting with trauma were admitted to general medicine teams, potentially without trauma team review, however this data was not recorded. There was a suggestion of a trend to longer LOS and functional decline in this group compared with those admitted under trauma. The lack of trauma team coordinated care including input from geriatric trauma specialists which only see patients admitted under trauma may contribute to this and be an area of improvement.
There is significant variation in the reporting of complications in the geriatric trauma population given the variability of the patient population as well variation in the types and definitions of complications reported. In this cohort, the rate of any complication was 44%. This is higher than previously reported [28], however rates are not directly comparable. Rates of complications were less than that seen in hip fracture populations using a similar definition of complications [13] which is unsurprising given the hip fracture population is an older, frailer group [29]. Recent studies have demonstrated that complications contribute to increased risk of mortality, and that the relative risk attributable to complications increases with increasing age and injury severity [30]. In this study, delirium was a common complication seen in a quarter of all patients. This is slightly higher than in other studies of trauma patients not requiring surgery [31]. Park et al., were able to demonstrate that rates of delirium were reduced following the introduction of a trauma pathway for older patients (RR 0.54, 95% CI 0.37 to 0.80), suggesting that complications such as delirium are in part modifiable and can be targeted by interventions.
There is a paucity of evidence of trauma care for older adults within the existing trauma model, including on the benefit of trauma specialist centres and whether they provide value to the increasingly older demographic. Tonkins et al. identified only two studies in older persons with low impact trauma assessing the benefit of major trauma centres over lower-level centres [7]. They report that the results were discordant and highlighted the need for research to ensure that a trauma response system, including hospital care, is fit for purpose for the increasingly predominant demographic of trauma presentations (low impact trauma in an older person).
Novel models of care involving geriatricians working in partnership with trauma teams have arisen at the hospital level in recognition of the specific needs of older persons presenting with trauma. A recent meta-analysis on implementing geriatric trauma consultation by a geriatrician to patients admitted with trauma showed a reduced LOS of 1.11 days but no reduction in mortality [8]. Contrastingly however, a geriatric co-management model has recently reported lower mortality but with increased LOS [32]. This was in adults aged over 80 years of age and it was noted by the authors that the trade-off of lower mortality was an increased LOS and decreased discharge to previous residence (i.e. functional decline). In our study, patients admitted to “other” units without dedicated physician or geriatric input experienced longer LOS compared to being admitted under trauma with geriatric co-management. The impact of geriatric co-management on LOS requires further investigation.
The strengths of this study are that the cohort was defined using a large representative, dedicated geriatric specific trauma registry at a major trauma centre and includes patients of all causes of trauma (excluding isolated hip fractures) and across all units. Importantly, data on geriatric specific variables including function and complications were available for analysis. This makes this study relevant to patients admitted with trauma as a whole, rather than subgroups.
However, limitations are acknowledged relating to the use of the observational study design that cannot determine causality. Data was obtained via chart review which may introduce further bias due to missingness or inaccuracies, including unreliable baseline on which to base hospital acquired complications such as delirium. This data set did not routinely collect frailty data across the cohort and is acknowledged as a limitation, however the inclusion of multiple other co-variates would have expected to have significant co-linearity with frailty including comorbidities, functional status and residential status. The observational study design leaves open the possibility of other unmeasured confounders, for example the impact of COVID-19, and limitations on the ability to assess longer term outcomes post discharge such as 30-day mortality and longer term functional recovery as further limitations. The results of this study relate to a single centre in an Australian capital city and may not be generalisable to other settings which could be explored in further studies.
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