Development and validation of LUPIN: a patient-centred self-administered tool to assess disease activity and patient-reported outcomes in systemic lupus erythematosus.

Objective: To develop and validate LUPIN, a self-administered, patient-centred questionnaire codesigned by patients and lupus specialists to assess disease activity and patient-reported outcomes in systemic lupus erythematosus (SLE).

Methods: LUPIN and the SF-36 questionnaires were distributed across 34 centres in both metropolitan France and overseas territories. Patients completed the questionnaire prior to their consultations. Physicians, blinded to patients' responses, assessed disease activity using SLE Disease Activity Index 2000 (SLEDAI-2K) and Physician Global Assessment (PhGA). Correlations and discordances between patient and physician assessments were analysed.

Results: Among 444 participants (85% women, mean age 45 years), the most common manifestations included joint (86%) and skin (72%) involvement; 35% had a history of lupus nephritis. While correlations between LUPIN scores and SLEDAI/PhGA were statistically significant but modest (r<0.39), stronger associations were observed with SF-36 domains for fatigue (r=0.65), pain (r=0.65), and physical function (r=0.69). In patients with active SLE (SLEDAI≥4; n=153), the correlation between LUPIN and clinical SLEDAI improved (r=0.53, p<0.0001). Discordances were primarily driven by patient-reported fatigue and pain, unrelated to suspected mechanical or central pain syndromes.

Conclusion: LUPIN effectively captures symptom domains that are often under-represented in conventional clinical indices and reflects the lived burden of disease in SLE. It offers a practical, scalable tool to support patient engagement, shared decision-making and individualised disease monitoring. A longitudinal digital study is underway to further assess its value in tracking disease fluctuations over time.