Introduction
Healthcare inequality remains a significant challenge, affecting treatment access and clinical outcomes for various patient groups. In rheumatoid arthritis (RA), disparities in the initiation of biological and targeted synthetic disease-modifying antirheumatic drugs (DMARDs) have been observed, particularly among older individuals, racial minorities, and those with comorbidities. While these therapies are essential for achieving disease remission and preventing complications, timely escalation remains inconsistent across different populations.
Most existing studies on treatment disparities have been conducted in the USA, where access to healthcare varies significantly based on socioeconomic factors. These studies also predate the widespread use of biosimilars, which have improved affordability. However, little is known about whether similar disparities exist in countries with universal healthcare, such as the UK, where treatment decisions are based on clinical need rather than financial capability.
This study investigates factors influencing the initiation of biological and targeted synthetic DMARDs among RA patients in England and Wales. Using data from the National Early Inflammatory Arthritis Audit (NEIAA), which tracks early inflammatory arthritis cases, we aim to assess whether healthcare inequalities persist despite the universal coverage provided by the National Health Service (NHS). Understanding these factors is crucial for ensuring equitable treatment and improving patient outcomes.
Methods
Study Design and Data Source
This observational cohort study used data from the National Early Inflammatory Arthritis Audit (NEIAA), a UK-wide program assessing early inflammatory arthritis care. Since May 2018, all NHS rheumatology providers in England and Wales have been required to submit data on newly referred patients aged 16 and older. We included rheumatoid arthritis patients enrolled between May 2018 and April 2022, with 12-month follow-up data. Ethical approval was not required, and patient representatives contributed to study design and dissemination.
Outcomes
The primary outcome was the initiation of a biological or targeted synthetic DMARD within 12 months of a patient’s first rheumatology appointment. Clinicians recorded this as a binary outcome (yes/no) at the 12-month mark, regardless of whether the treatment was later discontinued or changed.
Statistical Analysis
Baseline characteristics were compared between patients who initiated biological or targeted synthetic DMARDs and those who did not. Modified Poisson regression estimated associations between treatment initiation and factors like age, sex, ethnicity, socioeconomic status, smoking, and comorbidities. Missing data were handled using multiple imputation. Sensitivity analyses considered disease severity, autoantibody status, and treatment delays. Statistical analyses were conducted in Stata version 17, with power calculations ensuring sufficient sample size for detecting disparities.
Results
Between May 8, 2018, and April 30, 2022, the NEIAA enrolled 14,233 individuals newly diagnosed with rheumatoid arthritis, with follow-up data available for 6,098 (42.8%) on the initiation of biological and targeted synthetic DMARDs within 12 months. Of these, 508 (8.3%) started such treatments, primarily TNF inhibitors (79.3%), followed by JAK inhibitors (9.4%), rituximab (6.3%), IL-6 inhibitors (3.1%), and abatacept (1.8%). Those who initiated these treatments were generally younger (mean age 54.3 vs. 59.6 years), more likely to be female, Black, and current smokers, while being less likely to have cardiovascular disease or cancer. They also had higher baseline DAS28 scores and were more frequently seropositive for rheumatoid factor or anti-CCP antibodies. The initiation of conventional synthetic DMARDs within three months was similar between groups, though methotrexate-based regimens were more common among those who later started biological or targeted synthetic DMARDs.
In multivariable analysis, younger individuals were more likely to start biological or targeted synthetic DMARDs, with the likelihood being highest in those under 40 years. Ethnicity also played a role, with Black individuals more likely and Asian individuals less likely to receive these treatments compared to White individuals, even after adjusting for comorbidities, socioeconomic status, and smoking. Asian individuals had the highest seropositivity rates, while Black individuals had the highest baseline DAS28 scores. Sensitivity analyses confirmed that these disparities persisted despite adjustments for disease severity and treatment response. Other care quality metrics, such as timely diagnosis and initial treatment, were similar or better for Asian individuals, yet they were still less likely to initiate advanced therapies. Smoking status did not significantly impact treatment initiation.
Conclusion
This national cohort study found significant disparities in the initiation of biological and targeted synthetic DMARDs for early rheumatoid arthritis based on age and ethnicity. Older patients were less likely to receive these treatments within 12 months of diagnosis, even after accounting for comorbidities and disease severity. Among ethnic groups, Asian individuals were less likely than White individuals to start on these therapies, a disparity observed especially in Asian women. In contrast, Black individuals were more likely than White individuals to receive these treatments, though this was linked to greater disease severity at baseline. Despite the NHS providing universal healthcare access, these differences highlight underlying inequities that are not explained by socioeconomic status or initial treatment response.
Previous studies have shown racial disparities in DMARD use, with factors such as patient beliefs, medication concerns, and physician decision-making playing a role. South Asian patients, for example, often have more negative views of DMARDs and lower adherence rates due to concerns about side effects and a lack of culturally tailored communication. Additionally, older patients are less likely to receive aggressive DMARD therapy, possibly due to concerns about safety despite evidence of similar efficacy across age groups. These findings underscore the need for targeted interventions to ensure equitable access to treatment, including culturally sensitive patient education and clinician awareness to address biases in prescribing practices.
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