Background : Medication non-adherence is common among systemic lupus erythematosus (SLE) patients and is disproportionately higher among minorities. We aimed to examine the adherence gap between minority and Caucasian SLE patients and explore factors associated with non-adherence that may present avenues for intervention.
Methods : Cross-sectional data were obtained via survey and chart review from consecutive SLE patients with ≥ 1 scheduled lupus medication. The Medication Adherence Self-Report Inventory (MASRI) was used to estimate adherence in the preceding month from 0-100%. High Self-reported Adherence was defined as MASRI ≥ 90%. Pharmacy refill data in the preceding 3 months were obtained by phone calls. High Refills was defined as a medication possession ratio of 80% for all prescribed SLE medications. Additional covariates included: positive and negative affect, self-efficacy, patient-reported health status, patient-rated interactions with providers, rheumatic medication regimen complexity, SLE Disease Activity Index (SLEDAI), and physician global assessment for inflammatory (PGA1) and noninflammatory (PGA2) symptoms. Adherence groups were compared.
Results : 84 enrolled (37% Caucasians, 59% African American, 1% Native American, and 4% Hispanic). Median age was 42 (range 22-68), 95% were female, 49% had ≥ college education, and 49% had private insurance. 54 (64%) had High Self-reported Adherence, but only 42 (50%) had High Refills. Minorities had lower rates compared to Caucasians for both High Self-reported Adherence (55% vs 81%, p=0.02) and High Refills (40% vs. 68%, p=0.01). Among 52 taking disease modifying agents (DMARDs) including methotrexate, leflunomide, azathioprine, and mycophenolate, High Refill rate was only 46%, and the difference between minorities and Caucasians was even larger (35% vs. 73%, p=0.01). In this group, the Low Refill group had higher SLEDAI (4 vs 2, p=0.02), PGA2 (1 vs 0, p=0.04), and a trend for living with children (41% vs. 17%, p=0.07) compared to those with High Refill rates. There were no statistically significant differences between the DMARD High and Low Refill groups in terms of positive and negative affect, self-efficacy, patient-provider interactions, patient self-reported outcomes, and other clinical factors.
Conclusions : Significant racial disparities exist in lupus medication adherence, and the gap is even more substantial for patients taking DMARDs, medications crucial for the treatment of more severe lupus manifestations. This gap likely contributes to the known racial disparities in SLE outcomes. We did not discover potential modifiable factors in this small sample. Qualitative studies are needed to better understand this racial gap and to develop interventions that address racial disparities in SLE.