Objectives Hydroxychloroquine (HCQ) is a key therapy in systemic lupus erythematosus (SLE). Medication non-adherence is reported in up to 80% of lupus patients and results in increased morbidity, mortality, and health care utilization. HCQ levels are a sensitive and reliable method to assess medication adherence. Our study evaluated the role of HCQ level measurement in routine clinical care and its association with disease activity in a predominantly Hispanic population. Methods SLE patients from the Columbia University Lupus cohort treated with HCQ for ≥ 6 months and reporting medication adherence were included. HCQ levels were measured by whole blood high performance liquid chromatography. Non-adherence was defined as an HCQ level <500 ng/ml. The association between HCQ levels and disease activity measured by Systemic Lupus Erythematosus Disease Activity Index 2000 (SLEDAI-2K) was evaluated. Results One hundred and eight patients were enrolled; the median age was 38 years, 91% were female, and 63% were Hispanic. The median SLEDAI-2K was 4.3 (0–20). Forty-one percent of patients had an HCQ level <500 ng/ml consistent with non-adherence, of which 19% had undetectable levels. A higher SLEDAI-2K score was associated with low HCQ levels ( p = 0.003). This association remained significant after adjusting for depression ( p = 0.0007). Conclusion HCQ levels < 500 ng/ml were associated with higher disease activity and accounted for 32% of the SLEDAI-2K variability. HCQ blood measurement is a simple and reliable method to evaluate medication adherence in SLE. Reasons for non-adherence (levels < 500 ng/ml) should be further explored and addressed.

Background/purpose The LFA REAL™ is a measurement system for evaluating lupus disease activity from both clinician and patient perspectives. Patients’ viewpoints are captured using a patient-reported outcome (PRO) questionnaire. A series of visual analog scales are designed to rate disease severity and progress over the past 4 weeks. Brief instructions guide the patient to distinguish between active, potentially reversible symptoms and chronic pain or discomfort that are more likely due to damage. Beyond its simplicity and efficiency, the PRO can provide versatile assessments from a global, organ-based, and symptom-specific level. This paper describes the patient-centered approach used to evaluate the content validity of the LFA-REAL PRO. Methods The PRO was developed in accordance with FDA guidance. A two-phase qualitative study was performed with 25 lupus patients, 10 who participated in concept elicitation (Phase 1) and 15 in cognitive debriefing interviews (Phase 2). Qualitative data were analyzed using ATLAS.ti software v7.5. Upon completion of the interviews, participants completed the draft PRO and additional measures to characterize the sample. Results The mean age of participants was 45.6 and 88% were female, as expected in a lupus population. The mean SF-36 physical component score was 29.8 and the mean mental component score was 46.4. Phase 1 elicited symptom saturation and mapping of the draft PRO. Fatigue was reported by 100% of patients, highlighting its importance as a measurable domain. Additionally, 100% of patients spontaneously mentioned arthritis, which may be more important to this group than previously estimated, substantiating the approach of this PRO to break down components of arthritis into joint pain, stiffness, and swelling. Shortness of breath and fever were reported more frequently than expected. Phase 2 data demonstrated that participants found the instrument easy to use and offered recommendations to improve clarity, leading to adjustments in wording and formatting. Conclusions Results suggest that the LFA-REAL PRO has content validity and, with some modifications suggested by participants, is ready for quantitative validation, including tests of reliability, validity, responsiveness to change, and performance relative to other PROs used in lupus trials. After validation, the LFA-REAL system is intended for use in clinical practice and research. Electronic supplementary material The online version of this article (10.1186/s12955-019-1151-8) contains supplementary material, which is available to authorized users.