Racial Disparities in Medication Adherence between African American and Caucasian Patients With Systemic Lupus Erythematosus and Their Associated Factors.

Objective: Medication nonadherence is more common in African Americans compared with Caucasians. We examined the racial adherence gaps among patients with systemic lupus erythematosus (SLE) and explored factors associated with nonadherence.

Methods: Cross-sectional data were obtained from consecutive patients prescribed SLE medications seen at an academic lupus clinic between August 2018 and February 2019. Adherence was measured using both self-report and pharmacy refill data. High composite adherence was defined as having both high self-reported adherence and high refill rates. Covariates were patient-provider interaction, patient-reported health status, and clinical factors. We compared adherence rates by race and used race-stratified analyses to identify factors associated with low composite adherence.

Results: Among 121 patients (37% Caucasian, 63% African American), the median age was 44 years (range 22-72), 95% were female, 51% had a college education or more, 46% had private insurance, and 38% had high composite adherence. Those with low composite adherence had higher damage scores, patient-reported disease activity scores, and more acute care visits. High composite adherence rate was lower among African Americans compared with Caucasians (30% vs 51%, P = 0.02), and the gap was largest for those taking mycophenolate (26% vs 75%, P = 0.01). Among African Americans, low composite adherence was associated with perceiving fewer "Compassionate respectful" interactions with providers and worse anxiety and negative affect. In contrast, among Caucasians, low composite adherence was only associated with higher SLE medication regimen burden and fibromyalgia pain score.

Conclusion: Significant racial disparities exist in SLE medication adherence, which likely contributes to racial disparities in SLE outcomes. Interventions may be more effective if tailored by race, such as improving patient-provider interaction and mental health among African Americans.