Sex and age differences in isolated traumatic brain injury: a retrospective observational study

Abstract

Background Among the many factors that may influence traumatic brain injury (TBI) progression, sex is one of the most controversial. The objective of this study was to investigate sex differences in TBI-associated morbidity and mortality using data from the largest trauma registry in Japan. Methods This retrospective, population-based observational study included patients with isolated TBI, who were registered in a nationwide database between 2004 and 2018. We excluded patients with extracranial injury (Abbreviated Injury Scale score ≥ 3) and removed potential confounding factors, such as non-neurological causes of mortality. Patients were stratified by age and mortality and post-injury complications were compared between males and females. Results A total of 51,726 patients with isolated TBI were included (16,901 females and 34,825 males). Mortality across all ages was documented in 12.01% (2030/16901) and 12.76% (4445/34825) of males and females, respectively. The adjusted odds ratio (OR) of TBI mortality for males compared to females was 1.32 (95% confidence interval [CI], 1.22–1.42]. Males aged 10–19 years and ≥ 60 years had a significantly higher mortality than females in the same age groups (10–19 years: adjusted OR, 1.97 [95% CI, 1.08–3.61]; 60–69 years: adjusted OR, 1.24 [95% CI, 1.02–1.50]; 70–79 years: adjusted OR, 1.20 [95% CI, 1.03–1.40]; 80–89 years: adjusted OR, 1.50 [95% CI, 1.31–1.73], and 90–99 years: adjusted OR, 1.72 [95% CI, 1.28–2.32]). In terms of the incidence of post-TBI neurologic and non-neurologic complications, the crude ORs were 1.29 (95% CI, 1.19–1.39) and 1.14 (95% CI, 1.07–1.22), respectively, for males versus females. This difference was especially evident among elderly patients (neurologic complications: OR, 1.27 [95% CI, 1.14–1.41]; non-neurologic complications: OR, 1.29 [95% CI, 1.19–1.39]). Conclusions In a nationwide sample of patients with TBI in Japan, males had a higher mortality than females. This disparity was particularly evident among younger and older generations. Furthermore, elderly males experienced more TBI complications than females of the same age.

Gender Discrepancy in Patients with Traumatic Brain Injury: A Retrospective Study from a Level 1 Trauma Center

“…In traumatic SDH, gender was not influencing the hospital survival [15][16][17][18]; however, male gender was associated with a poor functional outcome in one study [14]. Although in-hospital mortality was comparable by gender, males ≥55 years had a higher mortality rate [19]. Moreover, this gender difference impact was evident in the age group of 10-19 years and those who aged 65 and above.…”

“…Crude and adjusted OR did not show that gender is a predictor of mortality among TBI patients. On the contrary, a recent study in 2021 from Japan showed that the adjusted OR of TBI mortality for males in comparison to females was 1.32 (95% CI 1.22-1.42) [ 19 ]. Moreover, this gender difference impact was evident in the age group of 10-19 years and those who aged 65 and above.…”

“…Furthermore, the estrogen hormone is a potent antioxidant, preserves autoregulatory functions, reduces neuronal excitotoxicity, activates the mitogen-activated protein kinase (MAPKs), and upregulates the antiapoptosis (that prevents cell loss) in females after injury [ 37 ]. A recent larger study from Japan on patients sustaining isolated TBI found that, among younger and older populations, male gender was associated with higher mortality compared to females [ 19 ]. However, differences in mortality after TBI by gender remain inconclusive in the literature.…”

“…Improved survival among the premenopausal women reported in some studies could be related to the effect of female sex steroids levels after TBI [21]. Sex hormones might reduce the intracerebral pressure and improve the cerebral perfusion pressure [19,35]. Although a metaanalysis revealed poorer outcome in females sustaining severe TBI than males, few studies reported better outcome after administration of progesterone, properly due to its effect as it reduces the cerebral edema and promotes a neuroprotection [9,14,[35][36][37].…”

Employment and accommodation needs and the effect of COVID-19 on men and women with traumatic brain injury

“…As such, accessibility to needed services is heavily reliant on the cause of TBI (e.g., access to automobile insurance or Workplace Safety and Insurance Board), availability of extended health insurance plans, and employment status and income. These factors have been shown to be influenced by sex and gender[13,52,53] and thus may disproportionally impact men and women with TBI, placing the financial burden on survivors and circumstantially limiting the sustainability of service participation. As such, understanding men and women's personal life andU n c o r r e c t e d A u t h o r P r o o f valued goals and expectations can enable the provision of resources and support services that are needed.…”