Prevalence and demographics of systemic lupus erythematosus and lupus nephritis among US children with Medicaid coverage, 2002-2004

Methods Children aged 5-19 years with SLE (> 2 ICD-9 codes of 710.0) were identified from Medicaid Analytic eXtract (MAX) data, containing all inpatient and outpatient claims codes for Medicaid patients for all 50 U.S. States, 2002-2004. Within this group, lupus nephritis was identified from billing codes for > 2 of a range of ICD-9 codes for glomerulonephritis, proteinuria and renal failure (PPV 88%, validated by Chibnik et al., 2009). We calculated the prevalence of SLE and lupus nephritis among Medicaid-eligible children and within specific sociodemographic segments.