title: Changes in healthcare utilization and costs associated with sildenafil therapy for pulmonary arterial hypertension: a retrospective cohort study.
abstract: BACKGROUND
  Little is known concerning the degree to which initiation of sildenafil for pulmonary arterial hypertension (PAH) impacts patterns of healthcare utilization and costs.
  
  
  METHODS
  Using a large US health insurance claims database, we identified all patients with evidence of PAH (ICD-9-CM diagnosis codes 416.0, 416.8) who received sildenafil between 1/1/2005 and 9/30/2008. Date of the first-noted prescription for sildenafil was designated the "index date," and claims data were compiled for all study subjects for 6 months prior to their index date ("pretreatment") and 6 months thereafter ("follow-up"); patients with incomplete data during either of these periods were excluded. Healthcare utilization and costs were then compared between pretreatment and follow-up for all study subjects.
  
  
  RESULTS
  A total of 567 PAH patients were identified who began therapy with sildenafil and met all other study entry criteria. Mean (SD) age was 52 (10) years; 73% were women. Healthcare utilization was largely unchanged between pretreatment and follow-up, the only exceptions being decreases in the mean number of emergency department visits (from 0.7 to 0.5 per patient; p<0.01) and the percentage of patients hospitalized (from 35% to 29%; p=0.01). The mean cost of all PAH-related medication was $7139 during pretreatment and $14,095 during follow-up (sildenafil cost during follow-up= $5236); exclusive of PAH-related medications, however, total healthcare costs decreased modestly (from $30,104 to $27,605) (p<0.01 for all comparisons).
  
  
  CONCLUSIONS
  The cost of sildenafil therapy may be partially offset by reductions in other healthcare costs.
authors.affiliation: Policy Analysis Inc, (PAI), 4 Davis Court, Brookline, MA 02445, USA. aberger@pai2.com
authors.forename: Ariel
authors.initials: A
authors.lastname: Berger
authors.forename: John
authors.initials: J
authors.lastname: Edelsberg
authors.forename: Simon
authors.initials: S
authors.lastname: Teal
authors.forename: Marko A
authors.initials: MA
authors.lastname: Mychaskiw
authors.forename: Gerry
authors.initials: G
authors.lastname: Oster
mesh_terms: D000328:Adult; D059019:Clinical Coding; D015331:Cohort Studies; D003695:Delivery of Health Care / Q000706:statistics & numerical data*; D065627:Familial Primary Pulmonary Hypertension; D005260:Female; D005500:Follow-Up Studies; D017048:Health Care Costs / Q000706:statistics & numerical data*; D006801:Humans; D006976:Hypertension, Pulmonary / Q000145:classification / Q000188:drug therapy* / Q000191:economics*; D007344:Insurance Claim Reporting / Q000191:economics / Q000706:statistics & numerical data; D007345:Insurance Claim Review / Q000191:economics / Q000706:statistics & numerical data; D008297:Male; D008875:Middle Aged; D010879:Piperazines / Q000191:economics* / Q000627:therapeutic use*; D011687:Purines / Q000191:economics / Q000627:therapeutic use; D012189:Retrospective Studies; D000068677:Sildenafil Citrate; D013450:Sulfones / Q000191:economics* / Q000627:therapeutic use*; D014481:United States; D014665:Vasodilator Agents / Q000191:economics / Q000627:therapeutic use
chemical_list: D010879:Piperazines; D011687:Purines; D013450:Sulfones; D014665:Vasodilator Agents; D000068677:Sildenafil Citrate