Effect of pericardial effusion on outcomes in children admitted with systemic lupus erythematosus: a multicenter retrospective cohort study from the United States

Objective: We sought to describe characteristics of children admitted with pericardial effusion (PCE) and systemic lupus erythematosus (SLE) and determine the association between PCE and outcomes of interest. Methods: We performed a retrospective cohort study of the Pediatric Health Information System (PHIS). Patients were included if they were admitted to a PHIS participating hospital from 2004 to 2015 with a diagnosis of SLE and age ≤18 years. Children with congenital heart disease or who had undergone heart surgery were excluded. PCE was the primary predictor variable; multivariable analysis was used to evaluate the effect of PCE on the following outcomes: mortality, length of stay (LOS), and readmission within 30 days. Results: There were 5679 admissions, of which 705 (12.4%) had PCE. Median age at admission was 15 years (interquartile range: 13–17). There were no significant differences for age or sex between patients admitted either with or without PCE. A significantly higher percentage of children in the PCE group were black compared with those without PCE (43% vs. 31%, p < 0.001). In multivariable analysis, the odds of a black patient having PCE were 1.7 higher than non-black patients (p < 0.001). In-hospital mortality was 2.5 times higher in children with PCE compared with those without PCE (p = 0.027). Those with PCE also had 1.5 greater odds of readmission within 30 days (p < 0.001). PCE was not associated with increased LOS (0.99, p = 0.753). Conclusion: PCE is common in admissions of children with SLE. There are disproportionately more black patients with SLE affected by PCE than non-black. PCE is associated with significantly higher mortality and rates of readmission.