To investigate the nationwide prevalence and incidence of serious infections among children with systemic lupus erythematosus (SLE) enrolled in Medicaid, the US health insurance program for low-income patients.
From Medicaid claims (2000-2006) we identified children ages 5 to <18 years with SLE (≥3 International Classification of Diseases, Ninth Revision [ICD-9] codes of 710.0, each >30 days apart) and lupus nephritis (LN; ≥2 ICD-9 codes for kidney disease on/after SLE codes). From hospital discharge diagnoses, we identified infection subtypes (bacterial, fungal, and viral). We calculated incidence rates (IRs) per 100 person-years, mortality rates, and hazard ratios adjusted for sociodemographic factors, medications, and preventive care.
Among 3,500 children with identified SLE, 1,053 serious infections occurred over 10,108 person-years; the IR was 10.42 per 100 person-years (95% confidence interval [95% CI] 9.80-11.07) among all those with SLE and 17.65 per 100 person-years (95% CI 16.29-19.09) among those with LN. Bacterial infections were most common (87%, of which 39% were bacterial pneumonias). In adjusted models, African Americans and American Indians had higher rates of infections compared with white children, and those with comorbidities or receiving corticosteroids had higher infection rates than those without. Males had lower rates of serious infections compared to females. The 30-day postdischarge mortality rate was 4.4%.
Overall, hospitalized infections were very common in children with SLE, with bacterial pneumonia being the most common infection. Highest infection risks were among African American and American Indian children, those with LN, comorbidities, and those taking corticosteroids.