The Unique Array of Factors Brought by Each Individual to an Injury

Experienced clinicians, patients and patient advocates, and rehabilitation specialists know that a variety of preexisting and current attributes of the patient, including physiological, interpersonal, and other critical factors, as well as family and community relationships, play key roles in how significant a TBI will be for the patient. In many cases, the role played by these attributes in determining the trajectory of immediate recovery; rehabilitation; and long-term physical, emotional, intellectual, spiritual, and social outcomes is as important as the nature of the injury itself.

Biomedical Aspects of a TBI

Biomedical aspects of a TBI include the nature of the forces and stresses acting on a person’s brain, the potential occurrence of traumatic hemorrhage and swelling, and the existence of co-occurring injuries. A person’s own physiological responses to the injury are also important in the context of their genetics and endocrine, metabolic, and immune systems. As described in Chapter 2, a majority of TBIs result in what have been termed “mild” injuries with less severe damage to the brain and lesser threats to long-term cognitive, motor, sensory, social, and psychological functions. A smaller number of TBIs have more consequential traumatic impacts and far-ranging effects.

Psychosocial and Ecological Aspects of a TBI

The role of factors beyond the nature of the physical injury lies within a construct that examines the “whole person” in relation to intersecting domains of physical and nonphysical personal characteristics, interpersonal family and immediate community relationships, and socioeconomic factors within the individual’s living environment. This construct was first formally described by Engel as the biopsychosocial model (Engel, 1977). Systems theory, including related socioecological models, similarly view health conditions through a framework that considers interactions among individual characteristics, interpersonal relationships, community settings, and wider societal policies, applying the model to prevention, public health, and clinical settings (see, e.g., Karriker-Jaffe et al., 2020; Register-Mihalik and Callahan, 2020; van Erp et al., 2019, and the Centers for Disease Control and Prevention’s [CDC’s] violence prevention efforts¹). In the context of TBI, an expanded bio-psycho-socio-ecological (BPSE) model includes the wide and complex array of qualitative and quantitative elements of the living and inanimate network within which each human lives and flourishes. The ecological dimensions of TBI also encompass economic forces, recognizing that challenges in U.S. health care and social systems, such as a scarcity of rehabilitation venues and limited insurance coverage, can limit a person’s access to care.

TBIs are not the only illnesses or injuries whose management and outcomes of care are influenced by various elements of a BPSE model. Chronic pain, diabetes, asthma, cardiovascular disease, various cancers, stroke, and Alzheimer’s disease and other dementias are among the many chronic health conditions that share this range of influence. In fact, one could argue that no significant survivable injury, illness, or combat-related wound is free of the influence of BPSE factors. For all of these conditions, biological, psychological, social, and human ecological factors play significant roles in the patient’s degree of suffering, extent of functional capacity, and even length of survival, and must be assessed and addressed if these illnesses and injuries are to be managed optimally. Improvement in the patient’s condition depends on more than a short-term medical-surgical model of treatment, even in the hands of the most talented clinicians employing the most advanced, state-of-the-art and science modalities.

The prism in Figure 3-2 represents these BPSE factors. The array of BPSE factors unique to each patient can “refract” that person’s trajectory after TBI, in some cases leading to outcomes that are better than initially anticipated and in some cases to outcomes that are worse. Collectively, these factors affect the process of recovery and the level of function ultimately achieved for an individual person. The BPSE construct is always present, but the balance of factors and their interactions can change over time for any one patient.

FIGURE 3-2

The BPSE prism. The prism represents the multiple dimensions—biological, psychological, sociological, and ecological—that interact with and influence a condition such as TBI. These dimensions encompass an individual’s biological (more...)

This multifactorial model of human health and well-being is increasingly being recognized as having a major effect at the population level. Direct clinical care may contribute only 20 percent of the overall well-being of a nation’s citizenry (Hood et al., 2016), with lifestyle and behavioral factors and social and physical determinants of health playing a more dominant role (NRC and IOM, 2013). Life expectancy, maternal–child health, and a variety of other objective measures of population health are strongly related to these factors, although no one factor plays a more dominant role than others in the U.S. population as a whole.

How the BPSE Framework Describes the Course of a Person’s Trajectory After TBI

A TBI can represent the start of a potentially lifelong experience with the long-term consequences of a brain injury, and one cannot predict with certainty at the time of the initial injury what the long-term effects of any one TBI might be for a given person. As reported by providers across the continuum of care, as well as patients and family members, the prism of the BPSE model plays an essential role in affecting outcomes and long-term function. An initial classification of a TBI in a range from less to more severe can be refracted into an array of outcomes, from very poor to very favorable. Illustrating this point, a person’s chances of immediate survival from the initial injury have been summarized by the comment, “Where you live actually can determine if you live.”²

Beyond immediate survival, people who live in rural communities or are injured in remote sites with austere resources for emergency response, evacuation to definitive care, and access to intensive care treatment, as well as those who live in some urban communities where social determinants of health³ can affect well-being, are less likely to receive prompt, comprehensive, long-term care and rehabilitation after TBI relative to people without these impediments. Factors in American social and political life that have existed for the duration of the republic’s history and have contributed to institutional racism and stratification of educational, economic, employment, residential, and other opportunities have had a serious impact on the optimal management of TBI among disenfranchised groups, including people of color and Native Americans, the poor, and those living in rural areas.

How the Influence of the BPSE Prism and Engagement with an Effective Health Care System Affect a Person’s Experiences with TBI Across the Lifespan

After a TBI has been sustained, an “ideal” or optimal treatment and rehabilitation pathway represents what is achievable for that person under the best of conditions. Any deviation from that ideal pathway results in an outcome that is less than optimal. The BPSE prism can steer a person’s recovery trajectory away from the ideal pathway, reflecting how the biological nature of the injury, psychological enablers or disablers, social influences (family, race, ethnicity, political, community, faith group, etc.), and the wider ecological environment all impact prospects for short-term survival and longer-term function and potential disability (see Figure 3-3).

FIGURE 3-3

Conceptual depiction of how BPSE elements can affect the trajectory after a TBI and the role of an effective health care system. The optimal treatment and recovery pathway for a person after experiencing a TBI represents the best outcome that is achievable (more...)

In Figure 3-3, an effective health care system provides the lens that refocuses a person’s pathway back toward the best possible recovery trajectory. This health care lens encompasses diagnosis, treatment, rehabilitation, and reintegration. Ideally, the lens is able to recognize a deviation, identify requirements for achieving improved care and outcomes, and adjust a person’s course accordingly. A person with TBI may need to engage with the health care system multiple times over the course of their lifespan as post-TBI recovery evolves.

While BPSE factors play a role in all phases of TBI management and in the ultimate outcome for each patient, success in incorporating a full understanding of these factors into a patient’s clinical course and functional end state has been limited. Any fundamental advances in understanding TBI and in improving prevention, diagnosis, treatment, rehabilitation, and recovery will require integrating BPSE factors into the management scheme and research agenda for TBI, and engaging not only the medical system but also research, financial, educational, community support, and other key elements.

As explored in subsequent chapters, however, the current system for understanding and managing TBI does not function optimally for everyone. Challenges include the heterogeneity of TBI; the need for further research; gaps in the handoffs and transitions that occur along the continuum of care; the need for involvement of multiple types of care providers; the variety of data and payment systems involved in TBI care and research; and the diversity of organizations and communities in which people live, learn, work, and play.

Disparities and Inequities in TBI Outcomes and Access to Care

Gender and Sex Differences in TBI Outcomes and Access to Care

Age Differences in TBI Outcomes and Access to Care

Rural and Urban Differences in TBI Outcomes and Access to Care

As noted earlier, the care received by individual TBI patients may vary depending on where they live or receive care. For instance, one study evaluated differences in TBI mortality across urban and rural areas in the United States and found that the TBI fatality rate was 13 deaths per 100,000 persons higher in the most rural compared with the most urban areas (Brown et al., 2019). The median fatality rate from all causes of TBI was 23 percent higher in rural than in urban areas, with the greatest differences at the ends of the spectrum of metropolitan and nonmetropolitan counties (Brown et al., 2019).⁸ Yue and colleagues (2020) found that the burden of TBI in terms of injury severity, outcomes, and survival is worse in rural than nonrural areas. Underlying factors include reduced or variable access to prehospital care, trauma centers, neurosurgical interventions, and rehabilitative services (Haarbauer-Krupa et al., 2021). Rural populations tend to experience longer delays in reaching care relative to urban populations, which affects long-term outcomes (Tiesman et al., 2007).

Individuals living in rural areas face unique challenges in accessing TBI care and achieving optimal outcomes. Rural areas are home to fewer people with access to fewer public resources compared with those living in nonrural areas. Thus, people in rural areas frequently rely on volunteer emergency response workforces and service providers. Furthermore, injuries occurring in rural areas often are sustained in remote settings with even more limited access to care. This remoteness is associated with greater delays in access to care, greater variability in hospital care capabilities, and the challenge of transporting patients to specialized trauma care when needed, as well as other economic and demographic challenges. For example, people living in remote areas may be older, less able to travel, or less able to afford travel for acute and post-acute care (Tiesman et al., 2007).

The term “rural” can be defined using various indices or criteria, but rural populations, however defined, frequently must contend with conditions of environmental austerity, such as geographic remoteness, isolation, and severe weather conditions. The similarities between these challenges faced by rural populations and those faced by the armed forces may present an opportunity for collaboration among rural providers, special operations medical staff, and wilderness organizations to develop best practices for trauma care in austere conditions.

In terms of health systems and the experiences of rural and urban health care providers, urban providers practice in higher-resource settings where patients are typically closer to the point of care, and these providers have relatively frequent opportunities to practice and maintain skills in providing critical care. In contrast, rural providers practice in lower-resource settings where patients are often injured in remote settings far from the point of care, and these providers therefore have fewer opportunities to practice and maintain critical care skills. Moreover, there are very few neurosurgeons located in rural areas. Most trauma experts working in so-called rural settings in fact work in urban Level I or Level II trauma centers, that is, urban hubs that serve surrounding rural areas. Unfortunately, these providers often lack a comprehensive understanding of how trauma care is provided in truly rural settings or the experiences of providers in those settings. During 2020, for example, the committee learned that no members of the American College of Surgeons’ Rural Trauma Committee worked in a rural center. Similarly, the report A National Trauma Care System: Integrating Military and Civilian Trauma Systems to Achieve Zero Preventable Deaths (NASEM, 2016a) mentions the term “rural” fewer than ten times, exemplifying the insufficient focus on rural trauma care systems.⁹

In fact, the typical conditions for highly rural trauma care are austere and often comparable to the conditions faced by deployed military personnel. Many medical centers in rural areas have fewer than 25 beds, and half of these centers are at least 75 miles from a Level I or II trauma center. Providers working in these rural settings have variable capability to treat severely injured patients, and data are sparse regarding the transfer of patients from rural settings to more capable trauma centers.¹⁰ Rural populations are doubly impacted by the lack of access to specialized trauma care. The current understanding of how best to treat TBI patients in rural settings is insufficient, and because these settings have reduced access to effective treatments, patients often do not receive the standard of care that is known to be effective in other settings.

In addition to the challenges associated with acute TBI care, access to post-acute and rehabilitative services is even more limited in rural areas. Comparing vocational rehabilitation outcomes between TBI survivors from rural versus urban settings, Johnstone and colleagues (2003) found that despite similar injury severity, neuropsychological test scores, and demographic characteristics, survivors residing in urban areas received significantly greater funds for basic needs required for full participation in the vocational rehabilitation program, as well as significantly more transportation assistance and on-the-job training.

The substantial burden of rural trauma highlights the need for additional study to evaluate the mechanisms of and possible solutions for the disparity between rural and urban trauma care and outcomes (Brown et al., 2019). Such studies might also have implications for trauma care in low- and middle-income countries.

A systematic approach to improved access to acute care for traumatic injuries in rural areas has been proposed.¹¹ The starting point for such a system could be a notification system that, upon the reporting of an injury, would transmit SMS notifications to a dispatch center that would have up-to-date status and capacity information for all nearby hospitals. Patients could then be directed to the nearest appropriate center capable of delivering optimal care for a given patient.

Racial and Ethnic Differences in TBI Outcomes and Access to Care

Racial and ethnic differences have been linked to disparities and inequities in TBI prevalence, outcomes, and access to care. Many of the leading causes of TBI, such as road traffic crashes and violence, occur more frequently among populations of color relative to their White counterparts. Illustrating this point, the ED admission rate for the White population was 66 per 1,000 in 2019, compared with 74 per 1,000 for the non-White population (WISQARS, 2019 query).¹² A retrospective cohort study of adults presenting to California EDs between 2005 and 2014, for example, found a 58 percent increase in TBI ED visits and a 34 percent decrease in the proportion of patients admitted to the hospital. Patients who were older adults, Black, and publicly insured had the highest visit rates (Hsia et al., 2018). Assaults, a leading cause of brain injury, occurred three times more often in Black people (10.7/1000) than in White people (3/1000) (WISQARS, 2019 query). Referral to inpatient posthospital care was lower for non-White patients and those without private insurance (Kane et al., 2014). Racial, ethnic, and socioeconomic disparities have also been identified among children who experience TBI. According to a 2006 study, among children under 10 in the United States who experienced a TBI related to a motor vehicle crash between 1995 and 2001, Black children experienced significantly higher rates of death and hospitalization compared with their White peers (Langlois et al., 2005).

A comprehensive literature review explored racial differences in post-TBI outcomes, as well as the potential causes of racial and ethnic disparities in TBI rehabilitation and postacute services (Gary et al., 2009). The review found that compared with their White counterparts, Black and Hispanic patients who experienced a TBI tended to have worse functional outcomes, were less integrated into their communities, were less likely to receive treatment, and were less likely to be employed. Black and Hispanic caregivers for people with TBI also reported experiencing greater burden, having more unmet needs, and using different types of coping strategies relative to White caregivers. The authors highlight emerging research that suggests racial and ethnic differences in TBI with respect to marital stability, emotional and neurobiological sequelae, and quality-of-life outcomes, although more research is needed to explore these associations.

Numerous studies have identified relationships of race and ethnicity to rehabilitation outcomes after TBI, including utilization of posthospital care, access to rehabilitation, functional status, community reintegration, and employment. This research has shown that survivors from racial and ethnic minority groups are significantly less likely to utilize posthospital health care after brain injury (Gao et al., 2018; Odonkor et al., 2021). For example, a study using data from the National Trauma Databank (NTDB) between 2012 and 2015 on more than 100,000 TBI survivors found that only 16.1 percent of Black patients and 12.5 percent of Hispanic patients with TBI had been discharged from acute care to inpatient rehabilitation, compared with 23.3 percent of White patients (Haines et al., 2019). Black survivors with TBI were more likely to be discharged from acute care to home and less likely to utilize outpatient physical medicine and rehabilitation (PM&R) services (Schiraldi et al., 2015). Compared with White TBI survivors, Hispanic survivors also experienced a lower likelihood of discharge to rehabilitation (Asemota et al., 2013; Budnick et al., 2017; McQuistion et al., 2016) or posthospital care (Kane et al., 2014) and lower odds of discharge to high-level rehabilitation services despite similar insurance coverage (Meagher et al., 2015). Moreover, Black and Hispanic versus White survivors had poorer disability ratings, functional independence scores, and community reintegration (Arango-Lasprilla et al., 2007a,b Hart et al., 2005), while Hispanic survivors were less likely to obtain employment or to receive on-the-job supports compared with European Americans (da Silva Cardoso et al., 2007).

Demographic data at the local and national levels are currently too limited to enable a full understanding of the needs of many minority communities. During the committee’s information-gathering workshop, for instance, Megan Moore from the University of Washington reported that there have been more than 400 studies on the impacts of structural inequities by race and ethnicity, but far fewer studies based on other facets of inequity.¹³ She noted that the literature on racial and ethnic differences in TBI often describes disparities in outcomes without adequately identifying the drivers of those disparities, and that even fewer address solutions. Research on these disparities is impeded by the pooling of many racial and ethnic groups in the TBI literature, resulting in gaps in personal/identity-related data. Moore stressed that more data are needed to support the research needed to fully understand these disparities by race and ethnicity, taking into account that not all disparities are differentially negative.¹⁴

To mitigate the underlying inequities that contribute to these disparate outcomes, it will be necessary to design interventions targeting post-acute care that are specifically tailored to these groups (Gary et al., 2009). At the patient and family level, interventions need to be shaped by an awareness of sociocultural conditions and traditions, as well as the impact of preinjury resilience on outcomes. At the provider level, interventions need to include cultural competency assessments and training that are specific to the needs of a diverse population of TBI patients. At the level of the health care system, strategies are needed for increasing the proportion of Black, Indigenous, and people of color (BIPOC) health care professionals who are part of multidisciplinary teams. To support these efforts, research will be needed to explore the foundational factors driving these disparities, such as discrimination and cultural incongruence (Moore et al., 2015).

Finally, resources for Black and Hispanic families facing TBI are limited, and it is often difficult to reach these communities, in part because they are not well represented in the TBI community. Information about TBI also needs to be made more broadly accessible by addressing language barriers, for example.

Examples of Other Factors Associated with Disparities After TBI

A variety of other pre- and postinjury social determinants of health, including unemployment, housing insecurity, and lack of health insurance, have been associated with disparities in TBI care and outcomes. Other factors, such as criminal history or substance abuse, may be stigmatized and can serve as additional barriers to TBI care and rehabilitation.

Lessons and Recommendations from Recent National Academies Reports Addressing Equity in Health Care

Several recent National Academies studies and workshops have explored strategies for advancing equity in health care systems (NASEM, 2016b, 2019a,b,c, 2021a,b). Although not directed specifically at TBI, many of the reflections and recommendations emerging from these sources are potentially applicable to efforts to increase equity in systems of care for TBI and may be worthy of consideration by the TBI community. These reflections and recommendations span a range of areas, including improving workforce education and performance monitoring, building interdisciplinary care teams, increasing access to care, forging institutional partnerships beyond health systems, reforming payment systems, and leveraging digital health technology and implementation science (see Box 3-1).

BOX 3-1

ADVANCING EQUITY IN HEALTH CARE SYSTEMS: APPLYING REFLECTIONS AND RECOMMENDATIONS FROM NATIONAL ACADEMIES CONSENSUS STUDIES AND WORKSHOPS TO TBI.

In 2017, the National Quality Forum published A Roadmap for Promoting Health Equity and Eliminating Disparities, highlighting four pillars: (1) identify priority disparity areas, (2) implement evidence-based interventions to reduce disparity, (3) invest in health equity performance measures, and (4) incentivize the reduction of disparities (NQF, 2017). These four pillars can also serve as a guiding structure for the design and implementation of strategies for reducing the impact of structural barriers and providing more equitable access to TBI care for those populations currently underserved. Adopting an equity lens to shape such efforts will require awareness of assumptions that constrain the way people perceive, understand, and feel the world (NASEM, 2016b), ingrained viewpoints and expectations that must be changed to achieve a more inclusive perspective. In some contexts, health care inequity can be framed most effectively as a systemic and unsustainable issue of moral justice that affects all of society, not just particular minority groups, improvements in which will yield benefits for all. In other scenarios, it may be more appropriate to leverage a value-proposition argument for improving diversity, equity, and inclusion.

Lessons from Care Systems That Minimize Disparities

The early phases of assessment and acute management of TBI for military personnel and athletes on sports teams, such as those in the National Football League (NFL) and selected other professional sports leagues, provide lessons for minimizing the effect of disparities on immediate management at the site of injury, as well as on the quality and location of definitive emergency care.

Injuries to some of these individuals occur in the most dangerous, remote, and inaccessible places in the world. In battle zones where military service members are wounded, priority is given to mitigating the limitations of available health care capacity with evidence-based TBI protocols, extensive medical and nonmedical training, and timely evacuation and definitive care. Assessment, reporting, and rest protocols are an important component of early phases of TBI management for active duty service members.¹⁵ TBI is considered a potential risk for all service members deployed to war zones, engaged in training, or participating in sports programs, as well as for athletes in high-risk professional and university sports programs.¹⁶ As a consequence, potential TBIs in combat or on the playing field are treated aggressively, particularly given the attention to TBI resulting from the past two decades of war in Southwest Asia and increased focus on the long-term effects of concussions in athletics.

After acute TBI care, mid- and long-term management of the consequences of TBI is affected by access to and the nature of specialty care and institutional, community, and educational rehabilitation. In the management of sports-related concussion, such modifiable factors as early identification and follow-up with a specialist experienced in TBI are associated with faster recovery and improved outcomes (Desai et al., 2019; Kontos et al., 2020; Master et al., 2020). For military service members, a Transition and Care Management Program for Veterans who have served since the terrorist attacks of 9/11 extends comprehensive care into their transition to civilian life. The Department of Defense’s (DoD’s) military care system and the facilities and programs of the VA strive to ensure the availability of a system of care that encompasses prevention, early recognition and treatment of a potential TBI, and access to long-term rehabilitation.

Testimony during the committee’s information-gathering sessions included examples of optimal management of health challenges with lifelong impacts. Optimal management of stroke, for example, relies on prompt recognition of its occurrence, rapid transport to a facility capable of performing appropriate brain imaging studies, and thrombolytic/hemostatic intervention (Powers et al., 2019). Failure to take these steps may result in early death or prolonged disability. Recovery and rehabilitation after stroke requires a multidisciplinary approach with active family and patient support and community engagement to achieve optimal function for the patient. BPSE factors also play important roles in achieving an optimal management scheme for pain care, and a comprehensive national program is currently under way aimed at combining the efforts of basic and clinical researchers, clinicians, community health and health care organizations, patient advocacy groups, and public and private funding sources to reduce the impact of these factors.¹⁷

Similarly, optimal management of Alzheimer’s disease relies on prompt identification and multidisciplinary engagement (Bradley et al., 2015). These efforts may forestall the full impact of neurodegeneration and promote patient function, reduce family and community suffering, and lessen individual financial impacts and community economic costs as the disease progresses. As with stroke management, a multidisciplinary approach with active family and patient support, as well as community engagement, is needed to achieve optimal function for the patient and reduce long-term secondary and tertiary effects. The access of individual patients and their supportive families and friends to these collective services is a function of BPSE factors that are being addressed on a national scale.¹⁸