Low socioeconomic status is known to significantly impact health outcomes overall . Social-economic status is defined as ‘an individual's social or economic standing’ and is often measured by income, education level, employment, and location of residence . Socioeconomic status can influence health by multiple pathways including reducing access to care overall and decreasing utilization of specialty services , reducing access to food stores , and worsening physical environments both at home and work . Low socioeconomic status is also associated with increased stress and chronic stress has been shown to impact immune function and is increased in sarcoidosis [5–7].
Sarcoidosis is systemic disease characterized by granulomatous inflammation . Sarcoidosis is an inflammatory multiorgan disease with a wide variety of clinical manifestations, often affecting people of working age . Patients suffer from a broad spectrum of physical symptoms of varying severity including cognitive impairment and disabling fatigue that impact function [9,10]. The burden and disability of sarcoidosis can result in significant direct and indirect economic consequences including unemployment, workdays lost, and medical bills [11,12▪,13▪]. Sarcoidosis is also associated with worse health-related quality of life (HRQoL) and increased mortality compared with those without sarcoidosis . Studies over several decades indicate that significant disparities exist in sarcoidosis outcomes by socioeconomic status, race, and gender .
In this review, we describe the known health disparities that exist among patients with sarcoidosis by socioeconomic status, race, and gender. We review the disease characteristics of sarcoidosis and explore the possible reasons for health disparities in sarcoidosis. We investigate the possible intersectionality among socioeconomic status, race, and gender in sarcoidosis and the role of stress in disparities. Finally, we suggest possible interventions including working with patient societies to create educational programs accessible for low-income patients and caregivers, targeting medication adherence and trust in physicians and the medical system, and ensuring access to high-quality care for all patients that may mitigate some of these disparities.
Individuals with low income are more likely to have worse morbidity and a higher mortality compared with their higher income counterparts. The disparities seen in sarcoidosis by income are similar to those seen in other diseases. Low-income individuals with sarcoidosis defined by either income below the poverty level or less than $20 000 a year are reported to have worse dyspnea , lower HRQoL [17▪▪], and significantly higher rates of new sarcoidosis related comorbidities [17▪▪]. Additionally, low-income individuals with sarcoidosis have been found to have lower lung function and higher rates of hospitalizations when compared with higher income individuals with sarcoidosis [18,19].
Individuals with sarcoidosis often require long-term treatment to prevent disease progression [20,21]. Glucocorticosteroids are first-line treatment based on consensus guidelines [21–23] but may be associated with significant side-effects and worse HRQoL [24,25]. Given this, treating physicians should develop familiarity with some of the alternative agents. Medications such as methotrexate, azathioprine, mycophenolate, and anti-TNF treatments are recommended as steroid-sparing agents when glucocorticosteroids are not tolerated [21,22,25,26]. However, steroid-sparing agents are not always effective and often require concomitant low-dose glucocorticosteroids treatment and frequent monitoring with blood work for possible toxicities. Steroid-sparing agents are more expensive compared with glucocorticosteroids and may be harder to obtain depending on location in the world and insurance system. Low-income individuals have been found to have more glucocorticosteroid-related comorbidities [17▪▪] and report significant barriers to care including difficulty obtaining medications in the United States . These findings may suggest that low-income individuals are more likely to receive glucocorticosteroids only regimens, which may result in lower HRQoL and more comorbidities. Hence, this may even increase the burden of sarcoidosis, and, furthermore, it might be expected that less improvement will be achieved in those patient with only access to glucocorticosteroids.
The diagnosis of sarcoidosis is associated with financial strain [12▪] and low-income individuals report more impact of the disease on family finances [17▪▪]. In a longitudinal study within Sweden, individuals diagnosed with sarcoidosis had similar earnings as the general population prior to diagnosis but experienced a 7% less earnings the year of diagnosis and significantly higher work loss days in the five years after diagnosis . Low-income individuals with sarcoidosis are less likely to report normal physical functioning  and report higher rates of job loss [17▪▪] suggesting a disproportionate impact of the diagnosis on this population which may result in poorer health outcomes.
Additionally, individuals diagnosed with sarcoidosis face problems with disability claims [13▪]. Sarcoidosis patients may be more severely disabled than current disability claims assessment protocols for sarcoidosis are equipped to measure; a sufficient extent of objective parameters appear to be lacking [13▪]. Hendriks et al.[13▪] showed a high proportion of sarcoidosis patients who had undergone a disability evaluation felt their concerns dismissed with many disagreeing with the assessment outcome. Sarcoidosis-related education is needed to enhance work-related medical examinations supported by guidelines that account for extent of sarcoidosis impact on functionality, and therefore work capacity.
Individuals with higher educational attainment and insurance have overall better health compared with individuals who have lower education and are uninsured [28,29]. In sarcoidosis, similar patterns are seen with lower education being associated with increased physical limitation from the disease, worse HRQoL, and more fatigue [16,24,30]. Additionally, individuals with sarcoidosis who do not have insurance have increased barriers to medication, worse dyspnea, and lower lung function compared with those with insurance . Individuals with heart failure and lower education have been shown to significantly benefit from self-management interventions compared with those of higher education level . Research is needed in sarcoidosis to identify on how clinicians and nurses can help individuals with low education better manage their disease or identify additional supports for their care.
Race has also been shown to be a significant determinant of disparities in general health status with Black individuals having worse outcomes compared with White individuals, especially in the United States . Genetic differences, socioeconomic differences, institutional racism, poor access to medical care, increased stress, and potential environmental exposures have been implicated as possible reasons for the known racial disparities [32,33]. Black individuals with sarcoidosis have higher mortality rates  and higher rates of hospitalizations [18,34▪,35] compared with non-Hispanic whites. Although genetic differences among the races have been reported in sarcoidosis and Black individuals have a higher incidence of sarcoidosis [20,36], the socioeconomic contributions to racial health disparities in sarcoidosis are prominent, especially in the United States.
As mentioned above, a study done in Sweden found that individuals who develop sarcoidosis experience significant financial strain especially during the year of diagnosis . In general as patients’ age, they are more likely to successfully withstand financial strain . Older individuals have more time to acquire savings for times of financial strain and in the United States, there are more social safety nets for older individuals compared with younger individuals. As reported by Rybicki et al., Black individuals are affected by sarcoidosis up to a decade earlier in life compared with non-Hispanic white, which may lead to a greater impact of the financial strain for Black individuals. Additionally, especially in the United States, there is an intersectionality between race and income as several studies have reported that Black individuals with sarcoidosis more likely to fall below the poverty line leading to additional disparities described above [18,39].
Sarcoidosis is an inflammatory disease that can lead to irreversible organ damage if left untreated because of a delay in recognition, poor adherence, or medication intolerance or unaffordability. Black individuals have more advanced sarcoidosis and more organs affected by sarcoidosis compared with non-Hispanic whites [18,40]. Blacks also have worse pulmonary function measured by forced vital capacity % predicted around the time of sarcoidosis diagnosis compared with non-Hispanic whites . The fact that Black individuals with sarcoidosis often have more advanced disease [18,40] could be explained at least partly by a decreased access to medical care leading to a delay in diagnosis. Although genetic differences may exist between the races, factors such as access to care and possible difference in occupational exposures may also contribute to the finding that Black individuals are less likely to have clinical recovery from sarcoidosis compared with non-Hispanic whites .
Although Black individuals with sarcoidosis require long term treatment more often compared with non-Hispanic whites , they are generally underrepresented in the clinical trials investigating treatment efficacy in sarcoidosis [43,44,45]. In individuals with unremitting pulmonary sarcoidosis who require treatment, continuous treatment has been shown to be superior to intermittent treatment in terms of modifying lung function . In addition to the barriers that may exist to obtaining steroid-sparing medications described above for low-income individuals, Black individuals with sarcoidosis have been reported to be less adherent to medications for sarcoidosis in general compared with non-Hispanic whites [46▪], which may also contribute to health disparities. Research in other diseases such as hypertension has shown that racial discrimination has been shown to lead to poorer medication adherence and worse trust among Black individuals  but needs to be considered in sarcoidosis, especially in the United States.
Sarcoidosis is probably more common amongst women, although this also appears to vary from country to country . The peak incidence of sarcoidosis occurs between the ages 20 and 40 in both men and women, with a second lower and broader peak in women between 45 and 65 years of age. With regard to gender differences, female patients showed more emotional problems as well as body care, sleep, and movement problems than males .
In sarcoidosis, females were reported to have higher rates of hospitalizations , lower lung function based on Forced Vital Capacity % predicted , higher rates of depressive symptoms , higher amounts of work loss , and worse HRQoL compared with males . In a study by De Vries et al. female patients reported the presence of more symptoms more often and the nature of these symptoms also differed from those of male patients. In addition, female patients had a lower QOL in the areas of physical and psychological health, particularly with regard to pain, sleep, positive feelings, self-esteem, bodily image, mobility, and daily life activities . Medication also differed between female and male patients. In patients with current symptoms, females were prescribed more eye drops, pain killers, and nonsteroidal anti-inflammatory drugs, while males received more frequently corticosteroids. Studies are needed to evaluate whether the differences in the present study between male and female sarcoidosis patients are caused by a subject selection bias or lifestyle differences; have a genetic, hormonal, or biological base; or just are an epiphenomenon.
Intersectionality between gender and race
An intersectionality, overlap of various social identities experienced by an individual or group, between gender and race has been described with Black females experiencing worse HRQoL in comparison to Black males with higher perceived discrimination among females [48,50]. Sarcoidosis is model disease to further investigate the intersectionality between gender and race as it is more common among females in all races compared with males with black females having the highest incidence overall . The disparities in hospitalizations rates and lung function exist for both Black and female individuals with sarcoidosis. Further investigation should be done to understand sex as a biological variable across the research spectrum and the possible intersectionality with race.
Financial strain, systemic racism, and gender biases have all been linked to increased levels of psychosocial stress. Stress has been identified as a top determinant of health disparities by the WHO . Perceived stress is significantly elevated among individuals with sarcoidosis . Stress occurs when an individual perceives that environmental demands are too taxing or threatening or that their ability to cope is limited . Low-income and minority individuals are more likely to report severe stress over their lifetime  and stress has been identified as a causal pathway linking socioeconomic status to adverse health outcomes . High levels of stress are linked with increased mortality , higher chronic disease prevalence , and lower Quality of life . Studies demonstrate biologic plausibility; mechanistic pathways include neurobiological pathways  and epigenetic changes  collectively leading to upregulation of inflammatory pathways and thereby health decline. Given that stress is reported to be high among patients with sarcoidosis , it is important to understand the potential contributions of social-environmental stress on immune function and health outcomes in sarcoidosis.
The clinical presentation and course of sarcoidosis can be very different among patients. The data presented in this review highlights the need to improve access to high-quality medical care for all patients with sarcoidosis regardless of age, gender, race, or socioeconomic status as an important avenue to address disparities.
The National Heart, Lung, and Blood Institute completed a workshop to define priorities to improve clinical care in sarcoidosis and cited addressing disparities as an avenue to improve clinical outcomes . Health disparities in sarcoidosis by socioeconomic status, race, and gender have been described for decades. Having low income and no or other public insurance may cumulatively discourage seeking medical care. However, little work has been done to identify the major causes of these disparities, identify potential mechanisms, and develop interventions to mitigate the socioeconomic, racial, and gender disparities that are widely prevalent. In fact, Black individuals are often underrepresented in the current research being done in sarcoidosis. As clinicians and researchers, we owe it to our patients to not only describe the disparities but to design interventions that may improve the disparities seen in sarcoidosis and be aware of the differences per country and in access to healthcare systems. As recently stated by Cozier et al., ‘It is clear that sarcoidosis is a diagnosis that patients and their families can ill afford.’
Possible avenues for patient-level interventions that may improve the socioeconomic disparities in sarcoidosis include interventions promoting self-management and education around symptom recognition, treatment side-effect management, and treatment options, creating patient educational programs that are accessible for low-income patients. Cooperation with patient societies is an avenue which should be explored to improve and develop educational programs for both patients and caregivers and make them more accessible. Interventions addressing racial disparities in sarcoidosis may include those targeted at improving medication adherence and trust in physicians and the medical system. Furthermore, given the association between stress and the immune system and high levels of perceived stress in sarcoidosis, integrating screening and addressing social determinants of health may be necessary to reduce overall stress and improve health. There is a need for targeted research to identify additional causes and mechanisms for disparities, including the role of stress and occupational exposures. Increasing awareness and innovative ways to increase access to high-quality care for all, but especially for vulnerable populations are essential. Additionally, advocating for national policies to improve access to medical care and treatment for all sarcoidosis patients in general may be an important avenue to addressing the disparities in sarcoidosis in countries in which these policies do not exist.
We would like to thank Taylor Brown for assistance with this review.
Financial support and sponsorship
M.S. was supported by the Pearl M. Stetler Fellowship Award during time of this manuscript development.
Conflicts of interest
There are no conflicts of interest.
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