Objective: We used an electronic monitoring system to quantify adherence to prescribed oral therapies by patients with systemic lupus erythematosus (SLE).
Methods: Participants were included from a larger longitudinal study cohort of 110 patients recruited from publicly-funded rheumatology clinics, 78 of whom agreed to have their SLE drug therapy electronically monitored for two years with the Medication Events Monitoring System (MEMS®, AARDEX Group). Adherence was determined as the percentage of days (weeks for methotrexate) the patient took the medication as prescribed by the physician. Collected data included SLEDAI; SLICC damage index for SLE (SDI); medical outcome study social support survey (MOS-SSS); Center for Epidemiologic Studies depression scale (CESD); and quality of life (SF-12).
Results: Ninety percent of the cohort was female, 45% were Hispanic, and 49% were African-American. Mean age was 36.3 years, disease duration was 5.9 years, SLEDAI score was 3.2, and SDI score was 0.9. Adherence was 62% for all drugs combined and did not differ significantly for individual medications. Patients with more depression (p < 0.02), and higher number of pills taken daily (p < 0.02) were more likely to be non-adherent. Only one-fourth of the patients had an average adherence of ≥80%; these patients had a better mental component score (SF-12) at 24 months than non-adherent patients (p < 0.01).
Conclusions: Electronic monitoring demonstrated that only one-fourth of the patients had an adherence rate ≥80%. Polypharmacy and depression were associated with non-adherence.