Where You Live Shouldn't Dictate Your Care: Multilateral Strategies Are Needed for National and Regional Equity in Psoriatic Arthritis Treatment

The cross-sectional study by Banbury et al in this issue of Arthritis & Rheumatology, entitled, “Where we live matters: varied disease burden and treatment in psoriatic arthritis in the United States” used the Rheumatology Informatics System for Effectiveness (RISE) registry to assess the clinical characteristics, social deprivation, insurance coverage, and medication use among patients with psoriatic arthritis (PsA) across different regions of the United States.1 This article reveals disparities in PsA care at a time when new therapies and medications are continuously being developed. To ensure equitable outcomes for vulnerable populations, it is critical that advanced therapies be distributed effectively across regions, practice settings, and insurance types, especially as current legislation may lead to millions of Americans losing health insurance coverage.2 Overall, Banbury et al found the cohort was composed of a higher proportion of women (58%) than men. Women with PsA were more likely to have high disease activity (HDA) and high multimorbidity compared to men yet were less likely to receive biologic disease modifying antirheumatic drugs (bDMARDs). In addition, Black patients with PsA, those with Medicare or Medicaid, and those who clustered within Medicaid-serving provider practices all had greater odds of HDA. Regionally, patients residing in the South and the Midwest had greater odds of HDA compared to those in the West and Northeast. When controlling for age and sex, patients in the Northeast had the lowest odds of HDA compared to the other regions. The authors also found regional differences in treatment practices. The Midwest had the lowest use of bDMARD therapy but the highest use of glucocorticoids and conventional synthetic DMARDs. Patients seen in RISE practices in the South and the Midwest had overall higher socioeconomic deprivation, as measured by the Area Deprivation Index (ADI), which may have contributed to decreased access to bDMARD therapy. Likewise, authors identified access to care challenges in the subset of patients with PsA receiving Medicaid and living in high ADI areas. Among 198 RISE sites, only 14 practices were shown to provide care for half of all Medicaid-insured patients with PsA in this registry, and only 20 practices were shown to care for half of all patients with PsA with high social deprivation. Although this study was likely underpowered to detect differences in treatment across specific ethnic and racial groups within the geographic regions studied, it captures a detailed overview of these disparities in the US. The RISE registry currently reports on the practices of over 1,000 rheumatology providers, representing a comprehensive view of treatment strategies across the US.3 Notably, the authors were the first to report important regional differences in PsA disease activity and treatment patterns in the context of the ADI. This aids in understanding the role of adverse social determinants of health in PsA treatment disparities. By incorporating neighborhood-level indices, this study shifts the focus from individual health behaviors to broader community-level factors that may be systematic and policy driven. An inherent limitation to the use of RISE is that most rheumatology practices that participate in the registry are in private and community practice settings.4 This may lead to a selection bias for patients who are more likely to be insured. Therefore, there may be an underrepresentation of patients with PsA that are on public insurance plans, such as Medicare and Medicaid. This is likely reflected in the fact that so few of the RISE practices care for the large majority of such patients. Moreover, the registry cannot currently assess differences in time to DMARD use, time to diagnosis, or chronicity of disease. These nuances could identify important temporal relationships between disease onset and DMARD administration across the regions. Similarly, this study only assesses distance from a patient's address to the practice, but it does not account for population density, practice size, or rural versus urban setting. These factors could further influence treatment patterns, as delivery of bDMARDs may be more challenging in rural settings. Lastly, the choice to dichotomize continuous variables such as ADI could have limited clinical inferences across the spectrum of socioeconomic status. In the US, the average annual incidence of PsA cases was estimated to be 8.5 per 100,000 between 2000 and 2017, with a point prevalence of 181.8 per 100,000 in 2015 and an increasing incidence in women.5 Despite the increasing prevalence and more severe presentations of PsA among women, authors found a concerning trend toward decreased bDMARD prescriptions among this population.6 Likewise, the authors showed higher odds of HDA among Black patients compared to White patients. The literature supports delayed treatment initiation and significantly longer time to DMARD therapy among Black patients newly diagnosed with PsA.7 Similar ethnic, racial, and regional disparities in outcomes are also observed in patients with systemic lupus erythematosus (SLE). Black/African American patients with SLE have significantly greater disease severity, multimorbidity, and mortality rates compared to White patients. Racial and ethnic minority patients with SLE also disproportionately reside in disadvantaged neighborhoods, as measured by the ADI, which is notably a risk factor for poor retention in care.8 Patients with SLE living in the Northeast were also shown to be more likely to receive immunosuppressive therapy than those residing in the South. Given the parallels between SLE and this study's findings in patients with PsA, similar challenges may influence treatment outcomes across multiple systemic autoimmune rheumatic disease populations. In a 2021 Medicare and Medicaid database study, the prevalence of PsA was found to be 320 per 100,000 persons for Medicare enrollees and 132 per 100,000 persons for Medicaid enrollees.9 The 63% of patients enrolled in commercial insurance, the 38% of those enrolled in Medicaid, and the 21% of those enrolled in Medicare were prescribed biologic or targeted-synthetic DMARDs. Therefore, congruent with the findings presented by Banbury et al, access to these medications remains an unmet need for many patients due to limited insurance coverage and costs, among other factors.10 Numerous variables have been shown to perpetuate inequitable access to care; however, this study adds regional variations as a potential factor. This phenomenon may be attributed to a myriad of issues such as closure of local pharmacies, delivery limitations for bDMARDs in rural areas, or differences in Medicaid expansion across regions and states. However, even regional differences may be mitigated by insurance status. For example, a study of US veterans with rheumatoid arthritis showed smaller variations in bDMARD use between rural and urban dwelling patients. This is likely due to the more homogenous insurance coverage by the Veterans Affairs system compared to other payers.11 The 2018 ACR guidelines on PsA management stress the importance of early identification and initiation of therapy for improving long-term outcomes.12 Notably, the recommendations focus on immunomodulatory agents, such as DMARDs, for long-term management rather than addressing acute symptoms through intra-articular injections or systemic glucocorticoids. Similarly, in treatment-naive patients with active PsA, the use of tumor necrosis factor inhibitors is recommended over oral small molecules as a first-line option, especially in severe presentations. In addition, given the chronic and heterogenous nature of PsA, the use of bDMARDs and, more importantly, the individualization of PsA therapy is important. This necessity for personalized treatment plans emphasizes the importance of addressing regional medication access challenges in PsA care. Although the RISE registry highlights regional differences in the distance traveled to clinical rheumatology practices, regional differences in pharmacy access may also contribute to differences in bDMARD prescribing practices. Approximately 15.8 million people (4.7%) in the US live in pharmacy deserts, encompassing both rural and urban settings.13 Prior studies have illustrated these pharmacy deserts and their impact on observed disparities in treatment patterns. For example, the higher prevalence of pharmacy deserts in the Midwest and South were significantly associated with COVID-19 deaths during the pandemic (Figure 1).14 Moreover, neighborhood-level indices, like the ADI or the Social Vulnerability Index (SVI), may be used as tools to identify neighborhoods with disparities in PsA detection, treatment, and management. Greater socioeconomic disadvantage as measured by the SVI has been shown to be associated with lower screening rates for various conditions including cancer.15 Therefore, beyond provider practice settings, disparities in pharmacy access, social vulnerability, and screening may underlie the regional differences in access to medications. This study effectively identifies disparities and regional variations in treatment patterns in the US and offers a timely emphasis on the importance of addressing systemic barriers to care in PsA treatment. Systemic factors such as access to rheumatology practices and social deprivation are major drivers of care differences. Although systemic factors that influence geographic differences in prescribing patterns are critical to inform policy, individual-level provider/patient interactions can also impact disparities in care. This study highlights the importance of considering PsA across genders and racial and geographic groups for differences in treatment culture. Efforts to address these disparities will require interventions that encompass both individual and community-wide factors. Leveraging continuing medical education opportunities by national and regional rheumatology societies could ensure more uniform, evidence-based long-term PsA management and improved outcomes. Likewise, future studies investigating variables such as time to diagnosis and time to DMARD may be beneficial to provide a holistic assessment of treatment variations and equip individual providers with useful metrics to mitigate disparities within their own practice. All in all, the data presented by Banbury et al underscore the national and regional disparities faced by patients with PsA. It will be through integrative and multilateral approaches that we achieve equitable care for this patient population. No original data were shared in this editorial. Data for the figure can be downloaded from the US Census Bureau. All authors contributed to at least one of the following manuscript preparation roles: conceptualization AND/OR methodology, software, investigation, formal analysis, data curation, visualization, and validation AND drafting or reviewing/editing the final draft. As corresponding author, Dr Blanco confirms that all authors have provided the final approval of the version to be published and takes responsibility for the affirmations regarding article submission (eg, not under consideration by another journal), the integrity of the data presented, and the statements regarding compliance with institutional review board/Declaration of Helsinki requirements. Disclosure form. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. 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