Social Determinants of Health and Traumatic Brain Injury: Implications for Rehabilitation Service Delivery and Outcomes

Abstract

ALL WHO EXPERIENCE a traumatic brain injury (TBI) should have an equal opportunity to achieve full integration in their communities and experience maximal health and well-being following the event, irrespective of their individual characteristics (eg, race) and/or social status. However, as conceptualizations of disability have evolved, the rehabilitation community has developed an appreciation for the difficulties of achieving this worthy objective, recognizing that recovery from potentially disabling conditions, such as TBI, is inextricably tied to structural and social processes (eg, discrimination) that produce disparities in rehabilitation outcomes.1–3 While the importance of linking rehabilitation outcomes to environmental conditions was first proposed in Nagi's conceptual model of disability in 1965,2 a report published nearly 6 decades later (2022) by the National Academies of Sciences, Engineering, and Medicine (NASEM) documents persistent variation in TBI care quality and outcomes across social conditions (eg, rurality).4 To narrow such disparities, this same report included a recommendation to increase scientific investment in understanding the ways in which social determinants of health (SDoH) produce and perpetuate disparities in TBI care quality and recovery. According to the US Department of Health and Human Services, SDoH are “conditions in the environments where people live, learn, work, play, worship, and age that affect a wide range of health, functioning, and quality-of-life outcomes and risks.”5 SDoH span 5 broad domains: (1) economic stability (eg, housing instability); (2) education (eg, high school education); (3) health and healthcare (eg, access to services); (4) neighborhood and built environment (eg, quality of housing); and (5) social and community context (eg, discrimination).5 Disparities exist in part due to an inequitable distribution of power and resources at the societal level (ie, structural discrimination [eg, institutional racism]), leaving marginalized social groups at disproportionate exposure to social risk factors that shape their health and recovery.6 If the rehabilitation community is to achieve the worthy objective of ensuring that individuals across social strata receive necessary support to maximally recover post-TBI, it is imperative that the ways in which SDoH shape TBI care and recovery are better understood. Accordingly, we sought articles that focused on the ways in which SDoH shape rehabilitation service delivery, health status, and functional recovery post-TBI. Studies included in this topical issue illustrate the diverse and multilevel (eg, individual- and community-level) nature of social risk factors capable of impacting individuals with TBI across different stages of recovery (acute vs postacute) and populations (eg, pediatric vs older adult; military members vs. civilians). Taken together, findings weave a relatively cohesive narrative: recovery from TBI is inextricably connected to social forces, and such forces warrant increased attention in TBI care and research. A SUMMARY OF STUDIES INCLUDED IN THIS TOPICAL ISSUE Racial disparities Several studies in this issue document disparities in TBI care and outcomes among members of marginalized racial and ethnic groups. Bahraini et al7 conducted a population-based study of military members with mild traumatic brain injury (mTBI) to examine potential racial and ethnic disparities in mortality risk. Their data indicated that risk for death by suicide, drug overdose, and opioid overdose was substantially higher among military members who self-identified as “other,” a racial category that may reflect minoritized individuals whose self-conception of racial identity is outside the bounds of standard categories (eg, multiracial). In a study of individuals with moderate-severe TBI and chronic pain, Sander et al8 examined racial disparities in chronic pain-related treatment, pain severity, and pain-related disability. While the authors found no disparities in treatment history, non-Hispanic Black individuals had more severe pain and greater pain-related disability relative to non-Hispanic White individuals. Interestingly, racial disparities were more pronounced in the presence of other indicators of social risk (ie, older age; lesser education). Such intersectionality of multiple social risk factors,9 including racial and ethnic identity, was the primary subject of investigation in the study conducted by Starosta et al.10 Using latent class analysis, the authors identified 4 subgroups of patients hospitalized for TBI, distinguished based on race/ethnicity, age, insurance status, and primary language. Members of latent classes characterized by greater systematic disadvantage (eg, minoritized racial/ethnic group; older age) were less likely to access inpatient rehabilitation and were at greater risk for mortality. Finally, Mohammed et al11 examined racial and ethnic disparities in adherence to primary care provider recommendations for concussion in the pediatric population. They found that non-Hispanic Black patients and those who did not have private insurance were less likely to adhere to recommendations relative to non-Hispanic White patients and those with private insurance. Importantly, the authors highlight that race and ethnicity serve as proxy indicators of intersecting social risk factors (eg, systemic racism and poverty) that may adversely impact patient adherence. The above studies can inform subsequent exploration of the specific factors producing suboptimal care quality and outcomes within marginalized racial groups, thereby achieving equitable service delivery and outcomes. Community-level SDoH Illustrating the multilevel (eg, individual; community) nature of SDoH, 2 studies examined the relationship between community-level indicators of social risk and rehabilitation service delivery and outcomes, revealing mixed findings. Bukhari et al12 investigated whether timely access to occupational and physical therapy services among those hospitalized with TBI was associated with rurality, and community-level income and educational attainment. Individuals hospitalized with TBI who lived in communities with greater educational attainment received physical therapy more quickly, but other hypothesized relationships were not supported. Miller et al13 revealed more robust support for the relationship between community-level social risk and mTBI recovery. The authors leveraged a composite measure of 17 indicators of neighborhood disadvantage (eg, education; housing quality), the Area Deprivation Index,14,15 to examine the relationship between community-level social risk and symptom burden within the first 6 months following an mTBI. Those who lived in more disadvantaged neighborhoods experienced greater symptom burden than those residing in neighborhoods with more advantageous social conditions, even after adjusting for demographics, individual-level indicators of socioeconomic status, and injury characteristics. Taken together, these studies highlight the importance of rigorous investigation regarding the ways in which social and community context shape access to post-TBI care, as well as outcomes. Tailoring services for marginalized communities with TBI Two studies in this topical issue raise the important concern of tailoring existing services to the unique needs of individuals from minoritized communities living with TBIs. Wilson et al16 found that nonnative (ie, not born in the United States) individuals with TBI were offered fewer educational resources than US-born individuals, with such resources spanning critical topics, including information about “physical-cognitive health,” “understanding TBI,” and “healthcare services.” While the authors acknowledge that further work is needed to understand the mechanisms explaining these disparities, they offer several plausible explanations (eg, lack of trust in the healthcare system), and identify the importance of tailoring educational material provision to the distinct needs of individuals who were born in other countries. Holliday et al17 leveraged a large Department of Veterans Affairs electronic medical record dataset to examine risk for TBI among veterans receiving justice-related services (eg, programs supporting veterans' reentry into the community), a population with disproportionate exposure to a variety of social determinants (eg, lack of education).18 Adjusted estimates reflect elevated risk for TBI in those seeking justice-related services relative to nonrecipients. The authors highlight that justice-related services may not adequately serve the needs of veterans with TBI, and describe the potential benefits of care models tailored to the unique needs of justice-involved veterans living with such injuries (eg, compensatory strategies for cognitive impairment). Subjective experience of SDoH While many of the above studies included “objective” measurement of SDoH (eg, neighborhood disadvantage), one study explored how TBI recovery may be shaped by the subjective experience of social risk. In a sample of individuals with a history of moderate-severe TBI, Venkatesan et al19 measured perceived discrimination, distinguishing between everyday experiences of discrimination (EED; ie, injustices perceived to be minor but recurring) and major experiences of discrimination (MED; ie, highly consequential injustices). Bivariate results indicated that both forms of discrimination were associated with reduced quality of life and more severe psychological and neurobehavioral symptoms. However, only EED remained associated with these outcomes after adjusting for relevant covariates. Interestingly, participants perceived that such discrimination was due to a diverse array of sources (eg, disability; race), illustrating that multiple sources of discrimination should be considered in efforts aimed at achieving equitable TBI recovery. FUTURE DIRECTIONS The articles in this issue elicited important insights regarding the potential influence of SDoH upon TBI care and outcomes. Nonetheless, as noted by authors throughout this issue, more work in this area is urgently needed if we are to make substantial progress toward achieving health equity. Foundational to better understanding the role of SDoH in shaping TBI care and outcomes is the consistent and accurate measurement of social risk. As pointed out in the NASEM report regarding the state of TBI care and research, to narrow disparities in TBI service delivery and outcomes, researchers must incorporate rigorous measurement of SDoH, particularly those amenable to intervention (eg, perceived cultural competence of staff).4 For example, capture of social risk using valid and reliable assessments within routine clinical settings could enable secondary analyses aimed at understanding relationships between SDoH, access to high-quality TBI care, and short- and long-term outcomes. The above efforts would be aided by the field achieving a consensus regarding universal and standardized assessments of social risk relevant to the rehabilitation of those living with TBI. Such an effort could enable cross-sample comparisons and the replication of findings crucial to developing the requisite knowledge base for this area of inquiry. Although findings presented add to evidence of disparities in TBI care and outcomes across SDoH, what continues to be urgently needed is empirical support for purported theories explaining such disparities—many of which were advanced by authors of studies included in this issue. For example, several studies revealed racial disparities in TBI care and outcomes.7,8,10,11 However, race and ethnicity are socially constructed categories that serve as surrogate measures of historical and structural marginalization that may shape TBI care and recovery in myriad, dynamic, and mutually reinforcing ways.20 As such, including indicators of race and ethnicity alone may be necessary, yet insufficient, for understanding the specific mechanisms underlying disparities in TBI service delivery and recovery. Importantly, purported theories for mechanisms explaining potential disparities should be informed by the lived experiences of individuals with a history of TBI and other indicators of social risk. Indeed, the NASEM report highlighted the vast potential of participatory research designs in ensuring that the issues most germane to these communities are identified and acted upon.4,21 Such advancement of theories and empirical support for the specific ways in which SDoH shape TBI care and recovery is crucial for the development of person-centered strategies aimed at narrowing disparities in outcomes among those with TBI. The pursuit of health equity in TBI rehabilitation is contingent upon the development and evaluation of interventions that are primarily aimed at narrowing health disparities. Consistent with calls from within other fields,22 we suggest that greater attention be paid to how SDoH shape rehabilitation efficacy, the ability of rehabilitation interventions to elicit theorized mechanisms of action, and the uptake of evidence-based interventions within routine rehabilitation service delivery. Interventions developed using methods aimed at maximizing internal validity (eg, strict exclusion criteria) may result in interventions being tested in homogenous populations that are not representative of those living with TBI who populate “real-world” rehabilitation settings.23 Indeed, studies in this issue suggest that individuals with TBI and social disadvantage may benefit from tailored care aimed at their unique needs.16,17 Further, implementation science methods should be applied to narrow health disparities by improving the uptake of evidence-based interventions in routine TBI service delivery, ensuring that all patients with TBI receive interventions with empirical support.4,24 Finally, there is a need to develop and test novel TBI service models across the continuum of care that seamlessly integrate social and rehabilitative services, systematically identifying and addressing both social risk and rehabilitative needs to improve short- and long-term outcomes. The development of such novel care models should be based on specific and empirically supported theories regarding the ways in which SDoH shape rehabilitation intervention effectiveness among those living with TBI, access to high-quality follow-up care, and ultimately TBI outcomes. Further, social services embedded in rehabilitative care should be based on evidence-based practices and tailored to the specific social risk factors theorized to influence TBI recovery. For example, a recent NASEM report describes 5 activities that could be adopted by rehabilitation settings to ameliorate social risk among individuals with TBI: (1) awareness (ie, identify social risks and assets); (2) adjustment (ie, tailor care to accommodate social needs); (3) assistance (ie, reduce social risk by connecting patients with relevant support); (4) alignment (ie, healthcare system-level efforts to synergize service delivery with social assets in the community); and (5) advocacy (ie, healthcare systems partnering with social care groups to shape policy).25 Such activities should be tailored to the distinct needs of particular care settings, and outcomes should be rigorously evaluated to enable continued optimization of service delivery. Ensuring that all individuals with TBI have an equal opportunity for full recovery, irrespective of their social status, should be a primary objective of TBI care and research. This will require substantial and sustained scientific investment aimed at understanding the ways in which SDoH shape TBI care and outcomes. The articles in this issue represent an initial scientific investment and outline a potential research agenda that can help narrow inequities. Furthermore, this topical issue highlights the urgency with which the TBI rehabilitation community should act to not only understand, but to also change, the systems, practices, and policies that have produced such disparities to achieve health equity for all patients with TBI.

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