ABSTRACT Systemic lupus erythematosus (SLE) is a multi-organ autoimmune disease that is 2-4x more common among Black that White persons. Black patients with SLE are 6-7x more likely to suffer from kidney failure and die 13 years younger. Exacerbating these disparities, Black patients with SLE also have worse medication adherence, which is partially explained by mistrust about medicines and the medical system. Trust can be built through effective patient-clinician communication, but unfortunately, effective adherence communication occurs sporadically, and Black patients experience poorer communication quality with clinicians and participate less in decision making in clinic visits. Adherence interventions in SLE to date have only had limited success with patient reminders and education and have not attended to the quality of patient-clinician communication nor focused on ameliorating racial disparities in SLE medication adherence. The long-term goal is to reduce racial disparities and improve health outcomes among patients with SLE. The overall objective of this proposal is to optimize the culturally appropriate delivery and test the effect of CO-LEADER (COmmunication for Lupus Equity in Adherence with DOSE-Nonadherence-SLE and Refill data), a simple and flexible intervention that combines clinician training in communication skills centered around the needs of Black patients to effectively utilized pharmacy refill data with patient-reported adherence barriers. Pilot data for CO-LEADER suggest that 1) it is feasible, 2) it can be performed with high fidelity, 3) it enables consistent adherence discussions with excellent patient-clinician communication, and 4) it improves medication adherence while reducing racial disparities. A Hybrid Type I design will be used to conduct a cluster randomized trial of CO-LEADER at 2 racially diverse rheumatology clinics. Informed by the Ecological Model of Patient-Centered Communication, the central hypothesis is that CO-LEADER enables clinicians to consistently discover and collaboratively address patients’ adherence barriers. More effective adherence discussions will then enhance shared understanding, therapeutic alliance, and trust, thereby improving medication adherence, particularly for Black patients. The aims of the study will compare important outcomes between clinicians randomized to CO- LEADER and usual care to test the effect of the intervention on 1) patient-clinician communication via clinic visit audio recordings and patient surveys, and 2) SLE medication adherence via pharmacy refill data. The study will also simultaneously evaluate relevant implementation outcomes to identify areas for improvement in the intervention’s delivery. This innovative proposal is the first to test a SLE adherence intervention with an eye for equity in patient-clinician communication and medication adherence. The proposal is significant because successful completion of the award will provide robust data on a culturally tail...