title: The prevalence and burden of systemic lupus erythematosus in a medicare population: retrospective analysis of medicare claims.
abstract: BACKGROUND
  Systemic lupus erythematosus (SLE) is a chronic autoimmune disorder which can affect multiple organs of the body, requiring ongoing disease management and healthcare resource utilization. The economic impact of SLE has not been evaluated in a Medicare population to date. This study was conducted to assess the prevalence of SLE and its burden in terms of healthcare resource utilization and costs in a US Medicare population.
  
  
  METHODS
  This was a retrospective observational study using Medicare medical claims data (5% random sample) for the period spanning 2003 to 2007. SLE patients were identified by having ≥2 medical claims with a primary or secondary diagnosis of ICD-9 code 710.0X. The earliest quarter of SLE diagnosis was defined as the index quarter. Prevalence of SLE, the proportion of SLE cases on disability benefits, and the contribution of SLE to new disability cases were evaluated. Healthcare resource utilization and direct medical costs (2008 US dollars) over 12 months were compared between a cohort of patients with SLE and a cohort without SLE matched on key demographics. Differences in outcomes between cohorts were assessed using McNemar's test for dichotomous variables and paired t-tests for continuous variables.
  
  
  RESULTS
  A total of 13,348 patients with SLE were identified. The prevalence of SLE was approximately 3 per 1000 Medicare beneficiaries. After matching, the sample consisted of 6,707 SLE and 13,414 non-SLE patients. On average, the SLE cohort compared with the non-SLE cohort had 2.4 times more physician visits, 2.7 times more hospitalizations, 2.2 times more outpatient visits, and 2.1 times more emergency room visits. A medical cost surplus of approximately $10,229 per patient per year in the SLE cohort relative to the non-SLE cohort was driven largely by inpatient hospitalization costs (p < 0.001).
  
  
  CONCLUSIONS
  SLE prevalence was 3 per 1,000 Medicare patients. Patients with SLE consumed significantly more health care resources with significantly greater costs compared with those without SLE. Added costs were largely attributable to inpatient hospitalizations. The Medicare population is an important target for efforts to improve SLE disease management and reduce costs.
authors.affiliation: GlaxoSmithKline, Research Triangle Park, Durham County, NC USA.
authors.forename: Cindy
authors.initials: C
authors.lastname: Garris
authors.affiliation: Bristol-Myers Squibb, Tampa, FL USA.
authors.forename: Manan
authors.initials: M
authors.lastname: Shah
authors.affiliation: Xcenda, Palm Harbor, FL USA.
authors.forename: Eileen
authors.initials: E
authors.lastname: Farrelly
keywords: Burden of illness; Cost; Disability; Healthcare resource utilization; Lupus; Medicare; SLE