title: A multicenter, retrospective pilot study of resource use and costs associated with severity of disease in glaucoma.
abstract: OBJECTIVE
  To examine resource consumption and the direct costs of treating glaucoma at different disease severity levels.
  
  
  METHODS
  Observational, retrospective cohort study based on medical record review.
  
  
  METHODS
  One hundred fifty-one records of patients with primary open-angle or normal-tension glaucoma, glaucoma suspect, or ocular hypertension (age > or =18 years) were randomly selected from 12 sites in the United States and stratified according to severity based on International Classification of Diseases, Ninth Revision, Clinical Modification codes. Patients had to have been followed up for a minimum of 5 years. Patients with concomitant ocular disease likely to affect glaucoma treatment-related resource consumption were excluded.
  
  
  METHODS
  Glaucoma severity was assessed and assigned using a 6-stage glaucoma staging system, modified from the Bascom Palmer (Hodapp-Anderson-Parrish) system. Clinical and resource use data were collected from the medical record review. Resource consumption for low-vision care and vision rehabilitation was estimated for patients with end-stage disease based on specialist surveys. For each stage of disease, publicly available economic data were then applied to assign resource valuation and estimate patient-level direct costs from the payer perspective.
  
  
  METHODS
  Average annual resource use and estimated total annual direct cost of treatment were calculated at the patient level and stratified by stage of disease. Direct costs by specific resource types, including ophthalmology visits, glaucoma surgeries, medications, visual field examinations, and other glaucoma services, were also assessed.
  
  
  RESULTS
  Direct ophthalmology-related resource use, including ophthalmology visits, glaucoma surgeries, and medication use, increased as disease severity worsened. Average direct cost of treatment ranged from $623 per patient per year for glaucoma suspects or patients with early-stage disease to $2511 per patient per year for patients with end-stage disease. Medication costs composed the largest proportion of total direct cost for all stages of disease (range, 24%-61%).
  
  
  CONCLUSIONS
  The study results suggest that resource use and direct cost of glaucoma management increase with worsening disease severity. Based on these findings, a glaucoma treatment that delays the progression of disease could have the potential to significantly reduce the health economic burden of this chronic disease over many years.
authors.affiliation: Duke University Medical Center, Durham, NC 27710, USA.
authors.forename: Paul P
authors.initials: PP
authors.lastname: Lee
authors.forename: John G
authors.initials: JG
authors.lastname: Walt
authors.forename: John J
authors.initials: JJ
authors.lastname: Doyle
authors.forename: Sameer V
authors.initials: SV
authors.lastname: Kotak
authors.forename: Stacy J
authors.initials: SJ
authors.lastname: Evans
authors.forename: Donald L
authors.initials: DL
authors.lastname: Budenz
authors.forename: Philip P
authors.initials: PP
authors.lastname: Chen
authors.forename: Anne L
authors.initials: AL
authors.lastname: Coleman
authors.forename: Robert M
authors.initials: RM
authors.lastname: Feldman
authors.forename: Henry D
authors.initials: HD
authors.lastname: Jampel
authors.forename: L Jay
authors.initials: LJ
authors.lastname: Katz
authors.forename: Richard P
authors.initials: RP
authors.lastname: Mills
authors.forename: Jonathan S
authors.initials: JS
authors.lastname: Myers
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Noecker
authors.forename: Jody R
authors.initials: JR
authors.lastname: Piltz-Seymour
authors.forename: Robert R
authors.initials: RR
authors.lastname: Ritch
authors.forename: Paul N
authors.initials: PN
authors.lastname: Schacknow
authors.forename: Janet B
authors.initials: JB
authors.lastname: Serle
authors.forename: Gary L
authors.initials: GL
authors.lastname: Trick
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016527:Drug Costs / Q000706:statistics & numerical data; D005260:Female; D005902:Glaucoma, Open-Angle / Q000191:economics* / Q000503:physiopathology* / Q000628:therapy; D017048:Health Care Costs / Q000706:statistics & numerical data*; D006295:Health Resources / Q000706:statistics & numerical data*; D006302:Health Services Research; D006801:Humans; D007429:Intraocular Pressure; D008297:Male; D008499:Medical Records / Q000706:statistics & numerical data; D008875:Middle Aged; D009798:Ocular Hypertension / Q000191:economics / Q000503:physiopathology / Q000628:therapy; D010865:Pilot Projects; D012189:Retrospective Studies; D012720:Severity of Illness Index; D015354:Vision, Low / Q000191:economics / Q000503:physiopathology / Q000534:rehabilitation