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.