The present study indicates that the management intensity of hospitalised patients with TBI decreased with advanced age and that low management intensity was associated with an increased risk of 30-day mortality. Thus, we cannot rule out that the higher mortality among elderly TBI-patients has an element of self-fulfilling prophecy.
Age and sex
Seventy per cent of our patients were men. The male preponderance was very clear in younger patients, while in older patients this difference was less pronounced. In patients ≥ 85 years there was a female preponderance. The total number of patients with TBI aged ≥ 55 years exceeded the number of patients < 55 years. In sum, there are still many young males admitted for TBI, but they are outnumbered by men and women ≥ 55 years. The age and sex distributions found in this study are in line with several recently published studies (3, 6, 31).
Age and comorbidities
In this study, increasing age was significantly associated with severe systemic disease, need for assistance in daily life, and the use of antithrombotic medication. The close association between older age and comorbidity is in line with other recent TBI studies (3, 32, 33). Antithrombotics are associated with increased risk of intracranial hematoma after blunt head injury, progression of intracranial hematoma, increased morbidity, and mortality in the TBI population (34–37). Based on observation in clinical practice, comorbidities appear to be a more important factor than age itself for treatment decisions in patients with TBI.
Age and injury mechanism
Falls were the most frequent injury mechanism, and the proportion of fall-related injuries increased gradually with increasing age, which is in line with other recent TBI studies (3). Thus, the typical trauma patient today is a man or woman ≥ 50 years old with a low-energy fall injury. The World Health Organisation has defined risk factors for falls, and these include polypharmacy, comorbidities, age > 80 years, impaired cognition (especially attention and executive dysfunction), impaired vision, and environmental factors (38, 39).
Age and injury severity
The severity of TBI, as assessed by GCS and HISS, tended to decrease with increasing age, whereas TBI severity assessed by the Rotterdam CT score showed a gradual increase in severity with increasing age. This discrepancy is somewhat surprising but may perhaps represent known limitations of GCS and HISS (i.e., they are poor discriminators of less severe TBI). However, an increased fraction of less severe TBI in older adults has been reported and been linked to more frequent low-energy traumas in this age group (3). This link is supported by the lower number of multiple traumas that we found among the older adults in our study (3).
Age and management intensity
As markers for management intensity in the different age groups, we used rates of TTA, advanced TBI imaging, invasive ICP-monitoring, ventilator treatment, surgical evacuation of mass lesion, and decompressive craniectomy. All six parameters showed a declining rate of administration with increasing patient age. The composite score of management intensity, as visualised in Fig. 2, demonstrates that increasing age was associated with reduced management intensity irrespective of head injury severity. Decompressive craniectomy was not included in the composite score, because it must still be regarded as a treatment with limited documented benefit and is a treatment hardly documented at all in patients ≥ 65 years (40, 41).
Invasive ICP-monitoring of patients with TBI, according to the recommendations by the Brain Trauma Foundation, has been proven beneficial (42). The reduced use of ICP-monitoring with increasing age has been reported before (10, 42), and a low rate of surgical evacuation of traumatic intracranial mass lesions in TBI patients ≥ 65 years is in line with previous reports (10, 43). Bus et al. suggested that the tendency to restrict surgical treatment in the elderly is because of presumed poor prognosis and may have acted as a self-fulfilling prophecy (43). Whitmore and colleagues wrote in 2012: “When all the costs of severe TBI are considered, aggressive treatment is a cost-effective option, even for older patients. Comfort care for severe TBI is associated with poor outcomes and high costs, and should be reserved for situations in which aggressive approaches have failed or testing suggests such treatment is futile” (21). Kirkman et al. published a study in 2013 on TBI in the elderly and presented national data from UK hospitals showing that time from admission to CT head imaging increased with increasing age, as did the likelihood of not being transferred to a centre with acute neurosurgical care facilities and being reviewed only by the most junior grade doctor.
Age and mortality
The 30-day mortality in this cohort of hospital-admitted patients with TBI identified by neuroimaging was 12%. In multivariate analyses, increasing age, increasing severity of head injury, and low management intensity were significantly associated with increased risk of 30-day mortality. These predictors of TBI mortality are in line with other TBI studies (30, 44–48). The associations between age, management intensity and mortality is intriguing and should be assessed in more detail in future studies, especially because the severity of TBIs tends to be lower in elderly patients than younger ones.
The two main findings in this study are the reduced management intensity with increasing age and the association between management intensity and risk of 30-day mortality. Whether this reduced management intensity in elderly patients represents well-considered treatment-limiting decisions in selected patients or suboptimal treatment remains unanswered. Thus, we cannot rule out the possibility that the high mortality and morbidity among elderly TBI patients might partly be explained by a self-fulfilling prophecy. The answer to this somewhat provocative question may probably be found in large multicentre comparative effectiveness studies like the CENTER-TBI in Europe and TRACK-TBI in the US (49, 50). There is also a need for more qualitative research addressing decision-making rules for treatment-limiting decisions in TBI patients among physicians, nurses, and other health care providers (51). During the last 30 years there has been a significant change in attitude to treating older patients for severe medical conditions, e.g. in cardiology, cancer, and degenerative spine conditions (52–55). Increased knowledge and improvements during the last decades in anaesthesiology, intensive care medicine, neurosurgery, advanced surgical techniques, and rehabilitation give us the opportunity to push the previous limits of TBI treatment (56–59).
Strengths and limitations
The present study includes hospital-admitted patients with acute TBI identified by neuroimaging. If patients are triaged after recommended guidelines, the vast majority of adult patients with TBI admitted to the hospital will have intracranial injuries identified by neuroimaging (25). Thus, the patients included in this study will most likely be representative of the majority of Level 1 trauma hospital-admitted patients with TBI.
A substantial number of trauma patients are first triaged at local hospitals in our health region. The referral practice of these patients to the level 1 trauma centre may depend on the age and comorbidities of the patients. Therefore, we have reason to believe that many older adults with comorbidities and severe injuries are never referred. If this is correct, the management intensity of patients with TBI in the upper age groups is even lower than reported in this study.
We present no direct proof that the high mortality among elderly TBI patients can partly be explained by a self-fulfilling prophecy. Nevertheless, we still believe it is appropriate at least to consider this possibility in light of recent data indicating the benefit of aggressive acute treatment and rehabilitation in older patients with TBI (18–23).