title: Hidden cost of rheumatoid arthritis (RA): estimating cost of comorbid cardiovascular disease and depression among patients with RA.
abstract: OBJECTIVE
  To examine resource utilization and direct healthcare cost associated with comorbid cardiovascular disease (CVD) and depression among patients with prevalent rheumatoid arthritis (RA) based on analyses of retrospective healthcare claims data.
  
  
  METHODS
  The index date was set as the first observed claim with an RA diagnosis. Patients were required to be >or=18 years of age, to have received RA-related treatment during the pre-index period, and to have 12-month pre- and post-index data. Based on pre-index utilization, patients were classified into 4 diagnosis groups: RA alone, RA+CVD, RA+depression, and RA+CVD+depression. Analyses focused on annual differences in costs between patients with RA alone and those with CVD and/or depression. A generalized linear model was applied to control for demographic and clinical characteristics and to estimate cohort-specific adjusted mean annual healthcare cost.
  
  
  RESULTS
  Of 10,298 patients, 8,916 had RA alone (86.6%), 608 had RA+CVD (5.9%), 716 had RA+depression (7.0%), and 58 had RA+CVD+depression (0.5%). All patients with CVD and/or depression incurred significantly higher followup costs compared with patients with RA alone. Adjusted annual mean healthcare costs were highest for RA+CVD (US$14,145), followed by RA+CVD+depression ($13,513), RA+depression ($12,225), and RA alone ($11,404). Although patients with CVD and/or depression had a greater rate of RA-related hospitalization, adjusted RA-related healthcare costs did not reflect any statistically significant differences as compared to the RA-alone cohort.
  
  
  CONCLUSIONS
  A significant proportion (13.4%) of patients with prevalent RA have comorbid CVD and/or depression. The presence of these conditions significantly affects annual healthcare costs as well as specific RA-related utilization patterns.
authors.affiliation: PharMetrics, Inc., 311 Arsenal Street, Watertown, MA 02472, USA. ajoyce@us.imshealth.com
authors.forename: Amie T
authors.initials: AT
authors.lastname: Joyce
authors.forename: Paula
authors.initials: P
authors.lastname: Smith
authors.forename: Rezaul
authors.initials: R
authors.lastname: Khandker
authors.forename: Jeffrey M
authors.initials: JM
authors.lastname: Melin
authors.forename: Amitabh
authors.initials: A
authors.lastname: Singh
mesh_terms: D001172:Arthritis, Rheumatoid / Q000191:economics* / Q000503:physiopathology / Q000628:therapy; D002318:Cardiovascular Diseases / Q000191:economics* / Q000503:physiopathology / Q000628:therapy; D015897:Comorbidity; D016208:Databases, Factual; D003695:Delivery of Health Care / Q000191:economics / Q000706:statistics & numerical data; D003863:Depression / Q000191:economics* / Q000503:physiopathology / Q000628:therapy; D017048:Health Care Costs / Q000706:statistics & numerical data; D006296:Health Services / Q000706:statistics & numerical data; D006801:Humans; D007345:Insurance Claim Review; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D014481:United States