Global burden of traumatic brain and spinal cord injury

Traumatic brain injury (TBI) and spinal cord injury (SCI) are devastating conditions with far-reaching physical, emotional, and economic consequences for patients, families, and society at large. In The Lancet Neurology, the Global Burden of Diseases, Injuries, and Risk Factors (GBD) 2016 TBI and SCI Collaborators provide a rigorous and comprehensive analysis of the global, regional, and national burden of TBI and SCI from 1990 to 2016.1GBD 2016 Traumatic Brain Injury and Spinal Cord Injury CollaboratorsGlobal, regional, and national burden of traumatic brain injury and spinal cord injury, 1990–2016: a systematic analysis for the Global Burden of Disease Study 2016.Lancet Neurol. 2018; (published online Nov 26.)http://dx.doi.org/10.1016/S1474-4422(18)30415-0Google Scholar In addition to providing point estimates for the incidence, prevalence, and years of life lived with disability (YLD) of TBI and SCI by country, the Collaborators examine how these measures have changed with time. This Article has several important messages that merit close consideration. First, the global age-standardised incidence (percentage change 3·6% [95% uncertainty interval 1·8–5·5]), prevalence (8·4% [7·7–9·2]), and YLD (3·6% [1·8–5·5]) rates for TBI rose significantly between 1990 and 2016. Although these rates did not change significantly for SCI between 1990 and 2016, the total number of patients living with SCI is also likely to be increasing because the global population is increasing. The main causes of these injuries across most geographical locations were falls and road traffic accidents, suggesting that interventions targeting fall prevention and improved road safety should be key public health priorities. Furthermore, policy makers and governments should be prepared to invest resources into centres specialising in multidisciplinary care for people with TBI or SCI, because available systems are likely to become overburdened. Infrastructural changes at a health-care-systems level might be necessary to establish appropriate clinical care pathways and improve timely access to quality care. Second, although the age-standardised incidence of TBI in 2016 was nearly 30 times greater than that of SCI (369 per 100 000 vs 13 per 100 000), the age-standardised prevalence of TBI was only about double that of SCI (759 per 100 000 vs 368 per 100 000), and the age-standardised YLD rate for TBI was lower than that of SCI (111 per 100 000 vs 130 per 100 000). These differences between TBI and SCI are probably because of the higher case-fatality rate of TBI (ie, higher acute mortality from injury), although this effect should at least be partly offset by the higher standardised mortality ratios for SCI (ie, poorer long-term life expectancy for those who survive SCI).2Middleton JW Dayton A Walsh J Rutkowski SB Leong G Duong S Life expectancy after spinal cord injury: a 50-year study.Spinal Cord. 2012; 50: 803-811Crossref PubMed Scopus (131) Google Scholar, 3Brooks JC Strauss DJ Shavelle RM Paculdo DR Hammond FM Harrison-Felix CL Long-term disability and survival in traumatic brain injury: results from the National Institute on Disability and Rehabilitation Research Model Systems.Arch Phys Med Rehabil. 2013; 94: 2203-2209Summary Full Text Full Text PDF PubMed Scopus (77) Google Scholar Nonetheless, we can reasonably conclude from these data that the long-term burden of SCI for patients, caregivers, health-care systems, and the economy exceeds that of TBI. Third, this study showed that the age-standardised incidence and prevalence of SCI remained stable globally from 1990 to 2016. However, with demographic shifts, the overall pattern and morphology of these injuries are likely to have changed despite stability in the overall incidence, and such changes in distribution might vary by geographical region. Therefore, it would be prudent to examine how the age composition and patterns and mechanisms of injury among patients with SCI (and TBI) have changed over time and across different locations. A US study,4Jain NB Ayers GD Peterson EN et al.Traumatic spinal cord injury in the United States, 1993–2012.JAMA. 2015; 313: 2236-2243Crossref PubMed Scopus (360) Google Scholar for example, showed that the mean age of patients who had an SCI rose from 40 years in 1993 to 50 years in 2012. An increasing proportion of injuries occurred in older patients (ie, ≥65 years) secondary to falls.4Jain NB Ayers GD Peterson EN et al.Traumatic spinal cord injury in the United States, 1993–2012.JAMA. 2015; 313: 2236-2243Crossref PubMed Scopus (360) Google Scholar Similar trends have been reported in other high-income countries, both for SCI5Lee BB Cripps RA Fitzharris M Wing PC The global map for traumatic spinal cord injury epidemiology: update 2011, global incidence rate.Spinal Cord. 2014; 52: 110-116Crossref PubMed Scopus (523) Google Scholar, 6Singh A Tetreault L Kalsi-Ryan S Nouri A Fehlings MG Global prevalence and incidence of traumatic spinal cord injury.Clin Epidemiol. 2014; 6: 309-331PubMed Google Scholar and TBI.7Peeters W van den Brande R Polinder S et al.Epidemiology of traumatic brain injury in Europe.Acta Neurochir. 2015; 157: 1683-1696Crossref PubMed Scopus (405) Google Scholar This shift in the demographics of SCI and TBI is important because the acute care and rehabilitation of older patients with SCI or TBI present unique challenges, the health-care resources consumed are greater, and the outcomes are poorer than those in young patients.8Ahn H Bailey CS Rivers CS et al.Effect of older age on treatment decisions and outcomes among patients with traumatic spinal cord injury.CMAJ. 2015; 187: 873-880Crossref PubMed Scopus (42) Google Scholar, 9Marquez de la Plata CD Hart T Hammond FM et al.Impact of age on long-term recovery from traumatic brain injury.Arch Phys Med Rehabil. 2008; 89: 896-903Summary Full Text Full Text PDF PubMed Scopus (143) Google Scholar For example, older patients often have substantial comorbidities, and hence might be less able than younger patients to tolerate the extensive surgeries that can be indicated for severe SCI or TBI.10Partridge JS Harari D Dhesi JK Frailty in the older surgical patient: a review.Age Ageing. 2012; 41: 142-147Crossref PubMed Scopus (440) Google Scholar The GBD 2016 TBI and SCI Collaborators' study was made possible by the resources and wealth of information contained within the GBD 2016 framework, and makes use of all accessible data, including inpatient and outpatient health records, literature studies, and survey data. The uniform modelling strategy (based on Bayesian algorithms) and calculation of age-standardised epidemiological estimates permit comparisons between countries with different population distributions. Limitations include potential underestimation of the true incidence of TBI, as the authors point out, because of the failure to capture cases of mild TBI or concussion in patients who do not seek medical care. Furthermore, without stratification of SCI severity—eg, by the American Spinal Injury Association Impairment Scale (AIS) or Frankel grading—the true burden of disability attributable to SCI is difficult to appreciate fully. The consequences of an AIS grade A (ie, complete) SCI, for example, are very different from those of an AIS grade D injury. With additional data from large regional, national, and international registries of patients with SCI, we hope that future iterations of this study will be appropriately positioned to provide more accurate and granular estimates of the burden of SCI. All in all, the GBD 2016 TBI and SCI Collaborators' study is a formidable undertaking and the authors are to be congratulated for this important contribution to the literature. This study serves as a sobering reminder that, despite improvements in access to, and quality of, trauma care, the effects of neurotrauma continue to loom large on a global scale. We hope, however, that, by illuminating the ongoing and profound effects of TBI and SCI internationally, studies such as this one will inspire and invigorate clinicians, researchers, and policy makers to redouble efforts to develop improved prevention and treatment strategies. We declare no competing interests. Global, regional, and national burden of traumatic brain injury and spinal cord injury, 1990–2016: a systematic analysis for the Global Burden of Disease Study 2016TBI and SCI constitute a considerable portion of the global injury burden and are caused primarily by falls and road injuries. The increase in incidence of TBI over time might continue in view of increases in population density, population ageing, and increasing use of motor vehicles, motorcycles, and bicycles. The number of individuals living with SCI is expected to increase in view of population growth, which is concerning because of the specialised care that people with SCI can require. Our study was limited by data sparsity in some regions, and it will be important to invest greater resources in collection of data for TBI and SCI to improve the accuracy of future assessments. Full-Text PDF Open AccessThe data to put neurology on top of the public-health agendaEvery January issue of The Lancet Neurology includes a special Round Up section. Its pages are a celebration of research achievements over the previous year. Our 2018 Round Up reveals a booming specialty, in which the pace of discovery is accelerating, and for which advocates are needed to raise awareness of this progress and bring in the investment to maintain the pace. But advocacy for brain health research requires good evidence and accurate numbers on its social relevance, and only a few subspecialties within neurology have effectively gathered epidemiological data to support calls for resources and funding. Full-Text PDF