Remission and low disease activity state prevent hospitalizations in systemic lupus erythematosus patients

Objective: The aim of this study was to determine whether remission and low disease activity state protect systemic lupus erythematosus patients from being hospitalized. Materials and methods: Patients from the Almenara Lupus Cohort were included. Visits were performed every 6 months. Variables were measured at each visit. Hospitalizations were evaluated in the interval between two visits. Remission was defined as: a SLEDAI-2 K of 0, prednisone ≤5 mg/day and immunosuppressants on maintenance dose; low disease activity state as: a SLEDAI-2 K of ≤4, prednisone ≤7.5 mg/day and immunosuppressants on maintenance dose. Univariable and multivariable interval-censored survival regression models were used. In multivariable analysis, possible confounders were gender, age at diagnosis, socioeconomic status, educational level, disease duration, antimalarial use, the Systemic Lupus International Collaborating Clinics/American College of Rheumatology damage index (SDI) and Charlson comorbidity index. Confounders were determined in the same visit as disease activity state. Results: Of the 308 patients, 92.5% of them (n = 285) were women, had a mean age at diagnosis of 34.8 (13.4) years and a disease duration of 7.7 (6.5) years. At baseline the mean SDI was 1.13 (1.34). A total of 163 of the patients were hospitalized. In the multivariable analysis remission (hazard ratio 0.445 (0.274–0.725), P = 0.001) and low disease activity state (relative risk 0.504 (0.336–0.757), P = 0.001) at baseline were found to decrease the risk of hospitalization in systemic lupus erythematosus patients. A total of 158 hospitalizations presented a discernible cause. Disease activity was the most common cause of hospitalization, with 84 admissions (53.16%), the majority, 38, was due to active kidney disease (45.23%). Conclusion: Remission and low disease activity state decreased the risk of hospitalizations in these systemic lupus erythematosus patients. Disease activity, particularly renal, was the most frequent cause of hospitalization.