title: Clinical comorbidities, treatment patterns, and direct medical costs of patients with osteoarthritis in usual care: a retrospective claims database analysis.
abstract: OBJECTIVE
  Comorbidities and resource utilization among patients with osteoarthritis (OA) in clinical practice have been infrequently characterized. The purpose of this study was to examine comorbidities, pain-related pharmacotherapy, and direct medical costs of patients with OA in clinical practice.
  
  
  METHODS
  This retrospective cohort analysis used medical and pharmacy claims data from the LifeLink™ Database. OA patients (ICD-9-CM codes 715.XX) were matched (age, gender, and region) with individuals without OA. Comorbidities, pain-related pharmacotherapy, and direct medical costs (pharmacy, outpatient, inpatient, total) were examined for the calendar year 2008.
  
  
  RESULTS
  The sample consisted of 112,951 OA patients and 112,951 controls (mean age: 56.9 [SD=9.5] years; 62% female). Relative to controls, OA patients were significantly more likely (p<0.0001) to have comorbidities, including musculoskeletal (84.3 vs. 37.1%) and neuropathic pain (22.0 vs. 6.1%) conditions, depression (12.4 vs. 6.4%), anxiety (6.6 vs. 3.5%), and sleep disorders (11.9 vs. 4.2%). OA patients were significantly more likely (p<0.0001) to receive pain-related medications, including opioids (40.7 vs. 17.1%), NSAIDs (37.1 vs. 11.5%), tramadol (9.8 vs. 1.8%), and adjunctive medications for treating depression, anxiety, and insomnia. Mean [SD] total direct medical costs were more than two times higher among OA patients ($12,905 [$21,884] vs. $5099 [$13,855]; p<0.001) and median costs were more than three times higher ($6188 vs. $1879; p<0.0001). Study limitations include potential errors in coding and recording; overestimation of the comorbidity burden; inability to link condition of interest, OA, with prescribed medications; and possible underestimation of the true costs of OA, because indirect costs were not considered and the direct costs were from a third party payer (commercial insurance) perspective.
  
  
  CONCLUSIONS
  The patient burden of OA was characterized by a high prevalence of comorbidities. The payer burden was also substantial, with significantly greater use of pain-related and adjunctive medications, and higher direct medical costs.
authors.affiliation: Avalon Health Solutions, Inc., 1518 Walnut Steeet, Philadelphia, PA 19102, USA. mgore@avalonhealthsolutions.com
authors.forename: Mugdha
authors.initials: M
authors.lastname: Gore
authors.forename: Kei-Sing
authors.initials: KS
authors.lastname: Tai
authors.forename: Alesia
authors.initials: A
authors.lastname: Sadosky
authors.forename: Douglas
authors.initials: D
authors.lastname: Leslie
authors.forename: Brett R
authors.initials: BR
authors.lastname: Stacey
mesh_terms: D000368:Aged; D000700:Analgesics / Q000191:economics / Q000627:therapeutic use; D015897:Comorbidity; D003365:Costs and Cost Analysis; D005260:Female; D005102:Health Expenditures / Q000706:statistics & numerical data*; D006296:Health Services / Q000191:economics* / Q000706:statistics & numerical data*; D006801:Humans; D007345:Insurance Claim Review / Q000706:statistics & numerical data; D008297:Male; D008875:Middle Aged; D010003:Osteoarthritis / Q000150:complications / Q000191:economics*; D010146:Pain / Q000188:drug therapy / Q000191:economics / Q000209:etiology; D012189:Retrospective Studies
chemical_list: D000700:Analgesics