Social Determinants of Health and Asthma

Abstract

Purpose of Review—

Social determinants of health play a major role in healthcare utilization and outcomes in patients with Asthma. Continuing to understand how these complex and interwoven relationships interact to impact patient care will be crucial to creating innovative programs that address these disparities.

Recent Findings—

The current literature continues to support the association of substandard housing, urban and rural neighborhoods, and race/ethnicity with poor asthma outcomes. Targeted interventions with community health workers (CHW), telemedicine, and local environmental rectifications can help improve outcomes.

Summary—

The link between social determinants and poor asthma outcomes continues to be supported by recent literature. These factors are both non-modifiable and consequences of institutionalized racist policies that require innovative ideas, technologic equity, and funding for groups most at risk for poorer outcomes.

Introduction

The Center for Disease Control and Prevention (CDC) defines social determinants of health (SDoH) as “conditions in the places where people live, learn, work, and play that affect a wide range of health and quality-of life-risks and outcomes” (1). The World Health Organization (WHO) takes this definition further and includes the “wider set of forces and systems shaping the conditions of daily life”(2). Examples of SDoH include socioeconomic status, environment, opportunities for employment and education, and access to healthcare services.

The differences in SDoH between racial and ethnic groups provide insight into the asthma health disparities we see today. Non-Hispanic Black Americans are disproportionately impacted by asthma, with an asthma-related death rate per million individuals nearly double that of all other racial and ethnic groups (28.7 NH Black, 15.2 American Indian or Alaska Native, NH White 10.8, Hispanic 7.3) (3). Poverty is also linked with higher prevalence of asthma (3). The disproportionate morbidity and mortality related to asthma in racial/ethnic minority and low-income populations are only a small sample of the complex interactions SDoH play in asthma care. In a 2021 comprehensive review, Grant et al. described many social determinants that contribute to asthma disparities (4). In their review, they highlighted the role of historical and structural racism in shaping the everyday lives of individuals from minority groups, including educational and employment opportunities, housing quality, exposure to environmental hazards, and access to healthcare services. The purpose of this review is to feature the recent literature on the impact of SDoH on asthma outcomes and the interventions that try to tackle the disparities caused by them.

How Structural Racism Created Social Disadvantage in America

The concept of race is a social construct and myth. In 1950, biologists, geneticists, psychologists, sociologists, and anthropologists came together to make a declaration through UNESCO that race has no biological base (5). Despite this social construction, race and racism have been shown to negatively impact both mental and physical health (6,7). Given the lack of biological basis for this impact, there must be other social factors that contribute to this disparity. Addressing the disadvantages created by structural racism can be a path forward towards health equity (8).

A fundamental example of structural racism can be seen in historically red-lined neighborhoods. In the early 20^th century, millions of African Americans migrated from the southern states to large cities for better employment opportunities (9). Due to housing shortages, the Federal Housing Administration (FHA) began promoting movement of White families to the suburbs where they were able to buy homes and build wealth. Restrictive covenants kept African Americans and other racial/ethnic minority groups from being able to leave the inner cities and purchase homes in suburban areas, resulting in urban concentration of minority populations (10,11).

The Home Owner’s Loan Corporation (HOLC) subsequently created maps that delineated areas of risk for capital investments and home mortgages. These “Residential Security” maps contained “redlined” areas that were deemed “Hazardous” and as such, individuals and families were denied access to credit based on the location of these properties (11,12), resulting in disinvestment in these communities, lowering of property values and concentration of poverty. These discriminatory practices from 80 years ago have present day impacts: 74% of previously labeled “hazardous” areas are low-to-moderate income neighborhoods today, and 64% of those neighborhoods are predominantly minority neighborhoods (12). Segregation into these neighborhoods has limited opportunities for multigenerational wealth, and subsequently has placed families in substandard housing with limited ability to repair and maintain housing (13,14).

The impact of structural racism is also evident in rural America. While rural areas tend to have higher levels of poverty when compared to their corresponding metro-areas (15), Black Americans, American Indian/Alaskan Natives, and Hispanics had the highest incidence of poverty in non-metro areas (15,16). To this day, suburban areas often restrict the construction of low-income housing developments, impeding the mobility of residents out of less desirable neighborhoods (17).

SDoH and Asthma-Related Health Disparities

Poverty has been extensively linked with increased asthma prevalence, emergency room visits, and hospitalizations for asthma exacerbations. People of lower socioeconomic status, particularly communities of color, tend to live in areas with poor air quality (18–20) and high air pollution levels due to increased density of industrial sites (20,21), closer proximity to major roadways (20,22–24), and bus depots (25). Exposure to byproducts of fossil fuel combustion is linked with increased asthma prevalence (26), exacerbations (27–31), and reduced lung function (32–35). Non-Hispanic Black populations are twice as a likely to live in poor housing than White populations (36), with even larger housing disparities observed in rural areas (37). Living in poor housing conditions was associated with increased rates of asthma hospitalization (38,39). Populations of color, living in high poverty neighborhoods, and lack of home ownership were associated with exposure to high levels of indoor allergens such as cockroach and mouse in homes (40–42)and schools (43–49). Racial and ethnic minority groups were also more likely to be sensitized to these allergens (50). Exposure to cockroach and mouse allergen in studies of inner city children was associated with increased asthma morbidity (51–54). Black race, high poverty and low education were associated with increased risk of secondhand smoke (SHS) exposure in children (55,56). Exposure to SHS was associated with increased odds of wheezing or asthma (57–60), low lung function (61–63), and increased frequency of asthma-related healthcare visits (64,65). Psychological stress (66,67), adverse childhood experiences (68,69), exposure to violence and low perceived safety were associated with increased odds of asthma (70) and poor asthma control in children (71,72). Populations of color were found to be at higher risk of stress and exposure to violence than White populations (73) and were more likely to experience violence (74,75) and adverse childhood experiences (74). Due to hospital closures and under-resourced public hospitals, low-income minority populations have reduced access to preventive care services, poor continuity of care (76,77) and higher reliance on the ED for asthma care (76,78,79). Black populations were less likely to receive guidelines-based care, including asthma controller medications (80–82).

Targeted Interventions to Meet These Communities Most at Risk

Tackling asthma in urban, rural, and minority communities requires unique and creative solutions. It is also important to acknowledge the institutional processes and racism that put these families in a position of risk for poor asthma outcomes and severe disease. We must also be sure to define these populations appropriately. For example, using definitions that are not inclusive can miss as many as 30 million rural individuals and mis-label them as “metropolitan” (83). Additionally, rural populations and regions are heterogenous with pronounced racial/ethnic and industrial diversity (84).

Most interventions tend to isolate the respective region of interest (urban vs rural); however, there are some interventional techniques that have worked in both communities. Community level interventions with community health workers (CHW), social workers, and/or respiratory therapists have shown an ability to improve medication presence in the home, improve regimen adherence, link patients to resources, decrease ED visits and hospitalizations, and improve lung function in both rural and urban populations (85–90). Home remediations and repairs have also been shown to decrease asthma symptoms and reduce healthcare utilization in urban and rural communities (14,90,91). Despite an initial monetary investment for these repairs, there is still a notable cost savings to society and the healthcare system from reduced healthcare utilization (90,91). They provide economic and social reparation for substandard housing, while also decreasing micro-environmental exposures that can lead to future exacerbations.

Better screening of SDoH

To best address issues of SDoH, physicians and teams must find acceptable ways to screen and address the issues that they find. Liebel et al. created a severe asthma multidisciplinary clinic with a team of CHW and local public health department support that screened for SDoH. Although a small group of 12 patients were enrolled into this specific screening program, 88 SDoH-related needs were found and there was a decrease in hospitalization days for kids enrolled in this program (89). In the inpatient setting, Schechter et al. screened for SDoH in patients admitted with asthma and found that 50% had food or housing insecurity, and 63.8% described inadequate living conditions (88). It is important that future studies continue to screen for SDoH in the inpatient and outpatient setting. Linking screening and interventions with well-established community assistance programs can help with optimizing support for patients and families.

Community Health Workers (CHW)

The use of CHW to assist with asthma management is not a novel intervention, and their utility has been documented extensively before (92–95). More recent work shows that CHW continue to be an invaluable resource in screening and intervening on SDoH. Pappalardo et al. showed that CHW can help with asthma medication presence in the home, administration technique, regimen adherence, and improved health utilization (85,86). When community workers were removed from care, presence of medications and medication adherence declined (85). Additionally, CHW have been shown to decrease school and workdays (87). A notable randomized control trial by Jonas et al. showed CHW improved symptom days for children with asthma (96). CHW should continue to be leveraged as integral pieces for individual and community level interventions in future studies addressing asthma care.

Housing interventions

The Community Asthma Prevention Program (CAPP) in Philadelphia is an example of targeted trigger remediation programs for homes with children who have asthma. In this pilot program, Bryant-Stephens et al. used a combination of CHW and community construction contractors to identify tangible home remediation and repairs. Remediation of housing conditions to limit indoor asthma triggers resulted in significant improvements in asthma-related healthcare utilization (14). As this was a pilot program with follow up data obtained during the pandemic when asthma emergency department and hospitalizations decreased (97), it will be important to determine how this program and other home remediation programs impact asthma healthcare utilization. Other housing interventions, such as decreasing exposure to mouse allergens in homes, has also been shown to increase pre-bronchodilator FEV₁ (98). Not all environmental remediations have shown benefit. Grant et al. showed that controller medication requirement did not change when an environmental control strategy was used in conjunction with medication titration as compared to medication titration alone (99). Despite this, we agree that these types of interventions can assist in not only improving asthma outcomes, but also assist in correcting the disparities created by structurally racist housing policies.

Neighborhood Level Interventions and Housing Mobility

Recent work has begun to highlight the implications of historically racist housing policies and their association with poor asthma outcomes. Historically redlined areas in California had higher levels of emergency room visits due to asthma and higher diesel particle emissions (100). In Grade D “hazardous” neighborhoods in Philadelphia, there were worse asthma outcomes and poorer air quality for black adults (101). In current Urban Atlanta neighborhoods with higher asthma ICU admissions, it was noted that those neighborhoods had greater social vulnerability, lower childhood opportunity, and an association with future ICU readmissions (102).

Housing mobility programs are ways that families placed in these poor living conditions can relocate to better resourced neighborhoods (103). After moving from neighborhoods of high poverty to low poverty, adults were found to have lower prevalence of diabetes, obesity and physical limitations (104). To our knowledge, there is not a study that looks at housing mobility and its impact on asthma outcomes. Although not truly a study on “Housing Mobility”, Takaro et al. showed that moving families into a new “Breathe Easy Home” improved asthma clinical outcome when compared to education alone (105). This study could be used as a surrogate for future studies looking to assess how housing mobility programs can help improve asthma outcomes.

Smart Technology and Telemedicine

Advancement in technology and telemedicine are reasonable solutions to provide access to communities most at need. In a recent review exploring how technology can impact asthma care, Mosnaim et al. explored the many ways technology and smart technology has been integrated into asthma clinical practice. Most notably, this review shows that bi-directional technology interventions (data received from the patient prompting a response from the intervention) have shown the most benefit in adherence for asthma medications (106).

The urgency and unpredictability of the pandemic provided a unique opportunity for telemedicine technology to become more accessible and readily available for providers. Telemedicine can increase access to specialists in areas where they were originally not available, limit drive times to clinical visits, and decrease time off work (107). Justvig et al. showed that using telemedicine allowed their clinical group to have more clinical touchpoints with patients when compared to pre-pandemic levels (108). Telemedicine can also be used to obtain frequent and high-quality spirometry in rural communities, further broadening the scope of how telemedicine can be used in the future (109).

Future Directions and Needs

There continues to be integral work describing the complex interplay of SDoH and Asthma. Despite a global pandemic, there continues to be creative solutions to address these underlying determinants in the realm of CHW, home remediations, smart technology, and telemedicine (Figure 1). As mentioned previously, the first step is to acknowledge the systemic disadvantages placed on communities most at risk for poor asthma outcomes. Future work should explore how housing mobility programs can impact asthma outcome. Additionally, these mobility programs should also assess how other factors such as poverty, and education impact healthcare utilization.

Figure 1.

Impact of Exacerbators and Interventions for Social Determinants of Health (SDoH) on Asthma Outcomes. Promising interventions are not able to tilt the scale until poverty and structural racism are addressed at a societal level.

Although there are many similarities between successful interventions in urban and rural communities, studies continue to separate these populations. More work should investigate broad and generalizable interventions as clinicians tend to take care of multiple different populations in their practice.

Technology and telemedicine are also promising approaches to improving asthma-related care. Future work should look at clinical touchpoints and healthcare utilization outcomes now that most pandemic-related masking and school restrictions have lifted. In addition, more work exploring the clinical “reach” provided by these technologies will be imperative in determining the true utility of this method of practice. It is important that solutions in this realm consider the downstream cost to families because limitations in access to these technologic advancements due to cost will be counter-productive for families stricken by poverty.

These creative interventions allow for both comprehensive and individualized solutions for patients and their families. A comprehensive systemic review and meta-analysis showed interventions that tackle social risk in children with asthma can decrease emergency room visits and hospitalizations, further supporting the work we do to decrease asthma disparities secondary to SDoH (110). While these interventions and assistance described in this review continue to be helpful, most are merely proxies for a larger systems issue that need to be addressed at a state and federal level. Until we address these systemic disadvantages on our patients, we may not be able to reach the level of asthma care we hope to achieve.

Key points.

• Social determinants of health (SDoH) play a major role in healthcare utilization and poor health outcomes among patients with Asthma

• Structural racism has led to an association of poor asthma outcomes with substandard housing in both urban and rural neighborhoods, and with race/ethnicity.

• Promising interventions to address the sequelae of SDoH include community health workers (CHW), telemedicine, and local environmental rectifications.

• Systemic disadvantages need to be addressed to fully overcome the impact of SDoH on asthma morbidity and mortality.