The impact of social determinants of health on the presentation, management and outcomes of systemic lupus erythematosus

Abstract

Disparities in SLE rates and outcomes have been attributed to genetic and hormonal factors, cigarette smoking and environmental pollutants. However, a growing body of research indicates that social determinants of health (SDH) also have substantial impact on the disparities that characterize SLE. According to the World Health Organization, SDH are defined as ‘the conditions in which people are born, grow, work, live, and age’, account for 30–55% of health outcomes, and adversely impact health outcomes among those of low socioeconomic status and stigmatized racial/ethnic groups. We reviewed the impact of key SDH on SLE presentation, management and outcomes, including income, education, neighbourhood factors, healthcare access, discrimination and social support. We found that adverse SDH conditions may lead to more severe SLE with increased morbidity and mortality, and that SDH affect SLE management by dictating the most feasible monitoring and treatment plan for each individual patient based on his or her specific life circumstances (for example, based on health insurance status, distance to nearest provider and/or drug affordability). SDH also have a significant impact on SLE outcomes, with worse disease and psychosocial outcomes associated with lower income level, lower educational attainment, disadvantaged neighbourhoods, lack of health insurance or public health insurance in the USA, travel burden to nearest provider, anti-Black racism and lower social support. Future efforts to improve the management and outcomes of patients with SLE must combat the societal, economic and political forces that perpetuate these inequities.

Rheumatology key messages.

• Social determinants of health (SDH) have a substantial impact on the disparities that characterize SLE.

• Adverse SDH conditions may lead to more severe SLE and may limit patients’ treatment options.

• Worse SLE outcomes are associated with lower healthcare access, income, education and social support.

Introduction

SLE is a multisystem autoimmune disease that disproportionally affects demographic groups that have suffered from social, economic, political, and healthcare marginalization and oppression. SLE is 9 times more prevalent among females [1], with typical age of onset during reproductive years [2]. SLE is 2–4 times more common in non-White populations globally [3], and in the USA, up to 67% of patients with SLE are non-White [4–9]. Additionally, areas of the USA with the lowest county-level socioeconomic status (SES) have the highest prevalence of SLE, even after adjusting for age, sex and race/ethnicity [9].

Non-White patients are also more likely to have severe SLE. Though a rare disease with an estimated US prevalence of 161 000–322 000 adults [7], SLE is the fifth leading cause of death in the USA for Black and Hispanic females aged 15–24 years and the sixth leading cause of death for Black and Hispanic females aged 25–34 years [10]. Black, Asian/Pacific Islander and Hispanic patients with SLE have significantly higher rates of LN [11]. Black and Hispanic patients with LN are also more likely to progress to end-stage kidney disease (ESKD) [12, 13]. Further examples of racial/ethnic disparities in SLE include higher rates of pregnancy complications among Black and Hispanic women with SLE [14], worse physical functioning among Black patients with SLE [15], and higher death rates, occurring sooner after diagnosis and at a younger age, among Black patients with SLE [16].

Disparities in SLE rates and outcomes have been attributed to genetic and hormonal factors, cigarette smoking and environmental pollutants [17]. However, a growing body of research indicates that social determinants of health (SDH) also have a substantial impact on the disparities that characterize SLE [18]. According to the World Health Organization, SDH are defined as ‘the conditions in which people are born, grow, work, live, and age’, account for 30–55% of health outcomes, and adversely impact health outcomes among those of low SES [19] and stigmatized racial/ethnic groups [20]. This article will review the impact of key SDH on SLE presentation, management and outcomes, including income, education, neighbourhood factors, healthcare access, discrimination and social support.

Income

In multinational studies, lower income level and poverty have been found to be associated with multiple adverse outcomes in SLE, including increased disease activity, organ damage, mortality, depression, and work loss or disability, as well as decreased physical functioning and quality of life [21–31]. Higher levels of financial strain have also been associated with depression onset among 682 women with SLE in the US-based Lupus Outcomes Study [32]. A subset of patients from this study who were living in poverty frequently reported that they were only able to manage their SLE during disease flares given daily competing demands, such as food and housing insecurity [33].

Education

A growing body of research indicates that lower educational attainment is associated with poor SLE outcomes. In a study of 562 Canadian adults with SLE, those that did not complete high school had an increased risk of work disability (30% vs 14%, P = 0.0001) and increased disease activity at study enrolment, after adjusting for age, race/ethnicity and sex (P = 0.014) [34]. A Chinese study of 904 therapy-naïve patients with SLE demonstrated that after adjusting for age, sex and disease duration, lower educational level (<9 years) was associated with higher disease activity (P = 0.001) [35]. Lower educational attainment has also been associated with work loss, medication nonadherence, missed appointments, lower health-related quality of life, lower physical functioning, and increased depression and anxiety among patients with SLE [27, 36–40]. We hypothesize that the association between lower educational attainment and work disability or loss is due to the types of jobs that people with lower education hold, which may be difficult to perform with a chronic illness. Indeed, a 2022 systematic review of work participation among 3800 employed adults with SLE found that more physical jobs and low job control were associated with increased work loss or disability [29].

Neighbourhood factors

Bartels et al. found that Black patients with SLE were 10 times more likely to live in the most disadvantaged neighbourhoods as compared with White patients with SLE, which was the strongest predictor for poor retention in SLE care [41]. Other studies have found that SLE patients report neighbourhood crime as a stressor that leads to higher disease activity [33], racial segregation and low neighbourhood SES are associated with depression in SLE [27, 42], and HCQ adherence is lower in residential codes with a higher percentage of Black residents and a lower percentage of hospitals [43]. Among patients with SLE, rural residence has also been associated with higher disease activity [44, 45], renal disease [44], mucocutaneous and musculoskeletal manifestations [45], and depression [46]. We hypothesize that higher disease activity among rural SLE populations is associated with poorer access to specialized care.

Healthcare access

Multiple studies have demonstrated an association between lack of health insurance or public insurance and poor outcomes among patients with SLE in the USA. The association between public health insurance and adverse SLE outcomes has not been described outside of the USA [47] and may be related to the lack of universal healthcare and an underfunded public healthcare system within the USA. Patients with Medicare or Medicaid insurance have been shown to have higher rates of 30-day readmissions and preventable lupus hospitalizations as compared with privately insured patients with SLE [48–51]. Public insurance has also been associated with healthcare fragmentation (receipt of care across multiple institutions), which is itself associated with increased risk of infections, cardiovascular disease, LN, ESKD and stroke [52]. Among patients with paediatric-onset SLE, public insurance has been associated with a >6-fold increased risk of ESKD or death [53]. In US nationwide studies of patients with ESKD due to LN, Medicaid and uninsured patients are less likely to be referred for kidney transplant [54] and less likely to receive initial peritoneal dialysis [55]. In addition to insurance status, studies of patients with SLE have found that travel burden to receive SLE care may lead to missed appointments, medication nonadherence, and higher levels of anxiety and depression among patients with SLE [56–58].

Discrimination

In a study of 427 Black women with SLE residing in Atlanta [Black Women’s Experiences Living with Lupus (BeWELL), derived from the GOAL (Georgians Organized Against Lupus) cohort], higher frequency of self-reported experiences of racial discrimination in domains such as employment, housing and medical settings was associated with higher SLE activity and damage [59]. In follow-up studies from the BeWELL cohort, hearing about or observing (vicarious) racism was also associated with increased SLE activity, even after adjusting for personal experiences of racism [60]. There was also a significant association between anticipating racism and SLE activity, and smoking was found to exacerbate this association [61]. Psychological distress was found to mediate the relationship between racism-related stress and SLE disease activity in the BeWELL cohort [62].

Social support

Multiple international studies have demonstrated that lower levels of social support are associated with adverse mental health and disease outcomes in SLE. A survey-based study of 246 patients with SLE in China found that age <18 years, single marital status, unemployed status and higher damage were associated with lower levels of social support, and patients with lower social support had significantly more anxiety and depression [63]. In the GOAL cohort of 437 Black women with SLE, limited social support was significantly associated with depression (P < 0.001) [64]. An Egyptian cross-sectional study of 80 patients with SLE found that perception of worse neighbourhood social cohesion was associated with depressive symptoms and higher disease activity [46]. Other studies have found associations between lower levels of social support and lower health-related quality of life and mental health scores [65, 66]. Qualitative studies of patients with SLE have also demonstrated that many patients with SLE feel their disease is invisible to others and report inadequate SLE care and validation [67] as well as negative social support including denial of illness and unwanted advice from others [68, 69].

Conclusion

In summary, SDH interact in complex ways (Fig. 1) and play a key role in SLE presentation as adverse SDH conditions may lead to more severe disease. SDH also contribute to SLE management by dictating the most feasible monitoring and treatment plan for each individual patient based on his or her specific life circumstances (for example, based on health insurance status, distance to nearest provider and/or drug affordability). SDH also have a significant impact on SLE outcomes, with worse disease and psychosocial outcomes associated with lower income level, lower educational attainment, disadvantaged neighbourhoods, lack of health insurance or public health insurance in the USA, travel burden to nearest provider, anti-Black racism and lower social support. The associations between SDH and adverse SLE outcomes are summarized in Table 1. Future efforts to improve the management and outcomes of patients with SLE must combat the societal, economic and political forces that perpetuate these inequities.

Figure 1.

Directed acyclic graph of the relationships between social determinants of health factors

Table 1.

Social determinants of health (SDH) factors that have been associated with adverse SLE outcomes

Adverse SLE outcome	SDH factor [References]
Increased SLE activity	Lower income level [27, 31]
	Lower educational attainment [34, 35]
	Neighbourhood crime [33]
	Rural residence [44, 45]
	Racial discrimination [59–62]
	Lower social support [46]
Increased SLE damage	Lower income level [21, 22, 25–28]
	Racial discrimination [59]
	Lower social support [63]
Mortality	Lower income level [21, 24, 26, 30]
	US Medicaid or Medicare insurance [53]
End-stage kidney disease	US Medicaid or Medicare insurance [53]
Lack of referral for kidney transplant	US Medicaid insurance or no insurance [54]
Failure to receive initial peritoneal dialysis	US Medicaid insurance or no insurance [55]
Decreased physical functioning	Lower income level [23, 27]
	Lower educational attainment [27]
Decreased quality of life	Lower income level [21]
Decreased health-related quality of life	Lower educational attainment [40]
	Lower social support [65, 66]
Depression	Lower income level [27]
	Higher financial strain [32]
	Lower educational attainment [38, 39]
	Racial segregation [42]
	Disadvantaged neighbourhood [27]
	Rural residence [46]
	Travel burden to receive SLE care [56–58]
	Lower social support [63, 64]
Anxiety	Lower educational attainment [38]
	Travel burden to receive SLE care [56–58]
	Lower social support [63]
Increased work disability or loss	Lower income level [29]
	Lower educational attainment [34]
Medication nonadherence	Lower educational attainment [36]
	Racial segregation [43]
	Disadvantaged neighbourhood [43]
	Travel burden to receive SLE care [56–58]
Missed appointments/poor retention in SLE care	Lower educational attainment [37]
	Disadvantaged neighbourhood [41]
	Travel burden to receive SLE care [56–58]
30-day hospital readmissions	US Medicaid or Medicare insurance [48, 51]
Preventable lupus hospitalizations	US Medicaid or Medicare insurance [49, 50]
Healthcare fragmentation	US Medicaid or Medicare insurance [52]

Data availability

No new data were generated or analyzed in support of this article.

Funding

This paper was published as part of a supplement financially supported by Janssen Medical Affairs Global Services, LLC, a part of the Janssen pharmaceutical companies of Johnson & Johnson.

Disclosure statement: The authors have declared no conflicts of interest.