title: The impact of flare on disease costs of patients with systemic lupus erythematosus.
abstract: OBJECTIVE
  To evaluate both direct and indirect costs of systemic lupus erythematosus (SLE) patients with and without flares from a societal perspective, and to investigate the impact of the severity and clinical manifestations of flares on direct/indirect costs.
  
  
  METHODS
  A retrospective cost-of-illness study was performed on 306 SLE patients. Participants completed questionnaires on sociodemographics, employment status, and out-of-pocket expenses. Health resources consumption was recorded by chart review and patient self-reported questionnaire. The total number of flares and involved organs during the preceding 12 months were recorded. Multiple linear regression was performed to determine the cost predictors.
  
  
  RESULTS
  Patients with flares were younger, had shorter disease duration, and had higher disease activity at the time of the assessment. The overall incidence of lupus flares was 0.24 episodes per patient-year. Patients with flares used more health care resources and incurred significantly higher annual direct and indirect costs. The mean total costs per patient-year were 2-fold higher for patients with flares ($22,580 versus $10,870 [2006 US dollars]; P < 0.0005). Multiple regression analysis showed that the number of flares was an independent explanatory variable associated with increased direct costs. Patients with multiorgan flares or renal/neuropsychiatric flares incurred higher direct costs compared with those with single-organ flares or with other organ flares.
  
  
  CONCLUSIONS
  Patients with flares incur higher direct and indirect costs compared with those without flares. Major organ flares incur higher disease costs than other organ flares. Treatments that effectively control disease activity and prevent flares, especially major organ flares, may reduce the high costs associated with flare in SLE.
authors.affiliation: Prince of Wales Hospital and The Chinese University of Hong Kong, Shatin, Hong Kong.
authors.forename: Tracy Y
authors.initials: TY
authors.lastname: Zhu
authors.forename: Lai-Shan
authors.initials: LS
authors.lastname: Tam
authors.forename: Vivian W-Y
authors.initials: VW
authors.lastname: Lee
authors.forename: Kenneth K-C
authors.initials: KK
authors.lastname: Lee
authors.forename: Edmund K
authors.initials: EK
authors.lastname: Li
mesh_terms: D000328:Adult; D017281:Cost of Illness; D003362:Cost-Benefit Analysis; D018450:Disease Progression; D005260:Female; D017048:Health Care Costs; D006295:Health Resources / Q000191:economics / Q000706:statistics & numerical data; D006306:Health Surveys; D006801:Humans; D016014:Linear Models; D008180:Lupus Erythematosus, Systemic / Q000175:diagnosis / Q000191:economics* / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D012189:Retrospective Studies; D012720:Severity of Illness Index