Long-term life expectancy in severe traumatic brain injury: a systematic review

Traumatic brain injuries (TBIs) pose significant challenges to public health, medicine, and society due to their substantial impact on victims, caregivers, and the community. While indicators like life expectancy or death rates provide insights into mortality and long-term outcomes, they fail to address how TBIs affect aging, neurological sequelae, cognitive impairment, and psychological or psychiatric disorders. Moreover, most studies are limited to North America, limiting the generalizability of findings across different social welfare systems. As a result, clinicians face difficulties in providing optimal care and prognosis, hindering the improvement of life quality for victims and caregivers and efficient public health service planning. This study aims to address these limitations by examining life expectancy, mortality rates, and long-term outcomes in severely injured individuals.

PubMed/Medline, Web of Science, Cochrane Library, Google Scholar, and PEDro search engines were systematically searched for studies investigating life expectancy and long-term outcomes in severe traumatic brain injuries. The final search date for all sources/databases was July 31, 2023. We conducted a systematic review, and only original research articles published in English were eligible for inclusion. After the screening process, data were extracted about life expectancy, follow-up, and conclusions.

This study analyzed 24 studies out of 343 identified. Life expectancy in the TBI population is lower than that of the general population. Older age and severity of functional impairments are major risk factors for mortality. Mortality rates are particularly high in the first two months. Mortality trends suggest a bimodal distribution, with a peak in the first five years followed by no further deaths until nine years after injury. The most influential factors include age, sex, trauma severity, independence in walking and feeding, time since injury, ventilator dependence, and cognitive and communication impairments. Respiratory and circulatory complications are among the leading causes of TBI-related deaths, followed by epilepsy, suicide, and respiratory infections.

Further research is required, considering the different long-term outcomes after TBI and their impact on families and society, to accurately estimate the life expectancy necessary for clinicians, caregivers, national health institutions, and medico-legal settlements.