title: SLE patients with renal damage incur higher health care costs.
abstract: OBJECTIVE
  To compare costs and quality of life (QoL) between SLE patients with and without renal damage.
  
  
  METHODS
  Seven hundred and fifteen patients were surveyed semi-annually over 4 yrs on health care use and productivity loss and annually on QoL. Cumulative direct and indirect costs (2006 Canadian dollars) and QoL (average annual change in SF-36) were compared between patients with and without renal damage [Systemic Lupus International Collaborating Clinics/ACR Damage Index (SLICC/ACR DI)] using simultaneous regressions.
  
  
  RESULTS
  At study conclusion, for patients with the renal subscale of the SLICC/ACR DI = 0 (n = 634), 1 (n = 54), 2 (n = 15) and 3 (n = 12), mean 4-yr cumulative direct costs per patient (95% CI) were $20,337 ($18,815, $21,858), $27,869 ($19,230, $36,509), $51,191 ($23,463, $78,919) and $99,544 ($57,102, $141,987), respectively. In a regression where the renal subscale of the SLICC/ACR DI was a single indicator variable, on average (95% CI), each unit increase in renal damage was associated with a 24% (15%, 33%) increase in direct costs. In a regression where each level in the renal subscale was an indicator variable, patients with end-stage renal disease incurred 103% (65%, 141%) higher direct costs than those without renal damage. Cumulative indirect costs and annual change in the SF-36 summary scores did not differ between patients.
  
  
  CONCLUSIONS
  SLE patients with renal damage incurred higher direct costs, but did not experience a poorer QoL. QoL may be more influenced by concurrent renal activity than accumulated renal damage, which can occur at any time and patients may gradually habituate to their compromised health state.
authors.affiliation: Department of Medicine, Division of Clinical Immunology/Allergy, McGill University Health Centre, 687 Pine Avenue West, V Building, Montreal, Quebec, Canada H3A 1A1. ann.clarke@mcgill.ca
authors.forename: A E
authors.initials: AE
authors.lastname: Clarke
authors.forename: P
authors.initials: P
authors.lastname: Panopalis
authors.forename: M
authors.initials: M
authors.lastname: Petri
authors.forename: S
authors.initials: S
authors.lastname: Manzi
authors.forename: D A
authors.initials: DA
authors.lastname: Isenberg
authors.forename: C
authors.initials: C
authors.lastname: Gordon
authors.forename: J-L
authors.initials: JL
authors.lastname: Senécal
authors.forename: L
authors.initials: L
authors.lastname: Joseph
authors.forename: Y
authors.initials: Y
authors.lastname: St Pierre
authors.forename: T
authors.initials: T
authors.lastname: Li
mesh_terms: D000328:Adult; D001499:Bayes Theorem; D002170:Canada; D015331:Cohort Studies; D003131:Combined Modality Therapy; D017281:Cost of Illness; D003362:Cost-Benefit Analysis; D005260:Female; D017048:Health Care Costs; D006801:Humans; D007677:Kidney Function Tests; D016014:Linear Models; D008180:Lupus Erythematosus, Systemic / Q000175:diagnosis / Q000191:economics* / Q000628:therapy; D008181:Lupus Nephritis / Q000175:diagnosis / Q000191:economics* / Q000628:therapy; D008297:Male; D008875:Middle Aged; D015337:Multicenter Studies as Topic; D011788:Quality of Life; D018570:Risk Assessment; D012720:Severity of Illness Index; D006113:United Kingdom; D014481:United States