title: Economic impact of tobramycin in patients with cystic fibrosis in a managed care population.
abstract: OBJECTIVE
  Guidelines recommend chronic use of tobramycin solution for inhalation (TSI) for cystic fibrosis (CF) patients with moderate-to-severe lung disease and persistent airway Pseudomonas aeruginosa. This study evaluated the economic impact of TSI in managed care CF patients.
  
  
  METHODS
  Patients (0-64 years) with ≥2 CF medical claims between 01/01/04-03/31/09 were identified. For TSI users, the index date was the first TSI claim in the period; for non-users, a pseudo-index date was determined and randomly assigned by simulating the distribution of index dates of TSI users. Maximum sample size was obtained for patients with ≥3 months pre- and ≥12 months post-index eligibility. Users were categorized by number of TSI prescriptions filled during 12-month post-index period as low (1 fill), medium (2-3 fills) and high adherence (≥4 fills). Differences in per member per month (PMPM) costs pre-index to post-index were analyzed using paired t-tests.
  
  
  RESULTS
  A total of 388 TSI users (mean age 19 years, 48% female) and 444 non-users (mean age 30 years, 54% female) met study criteria. In users, total and CF-related PMPM costs decreased $959 (17%) and $113 (3%), respectively, after starting TSI. Among TSI users, CF-related inpatient PMPM costs decreased by $1171 (49%; p=0.01), while CF-related prescription PMPM costs increased by $992 (p<0.01). CF-related inpatient PMPM costs decreased by $381 (38%; p=0.16) for low and $1425 (50%; p=0.21) for medium users and decreased by $1829 (51%; p=0.02) for high users.
  
  
  CONCLUSIONS
  Limitations include use of administrative claims data, small sample size due to disease rarity, random assignment of pseudo-index date to non-users and differences in baseline characteristics between TSI users and non-users.
  
  
  CONCLUSIONS
  All-cause and CF-related PMPM medical costs significantly decreased after TSI initiation. Among TSI users, total healthcare costs decreased, although not significantly, due to PMPM increases in prescription costs. A trend towards greater decrease in inpatient PMPM costs was observed with increasing TSI adherence.
authors.affiliation: HealthCore, Inc., Wilmington, DE 19801, USA. dwertz@healthcore.com
authors.forename: Debra A
authors.initials: DA
authors.lastname: Wertz
authors.forename: Chun-Lan
authors.initials: CL
authors.lastname: Chang
authors.forename: Judith J
authors.initials: JJ
authors.lastname: Stephenson
authors.forename: Jie
authors.initials: J
authors.lastname: Zhang
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Kuhn
mesh_terms: D000280:Administration, Inhalation; D000293:Adolescent; D000328:Adult; D000368:Aged; D000900:Anti-Bacterial Agents / Q000008:administration & dosage* / Q000191:economics / Q000627:therapeutic use; D002648:Child; D002675:Child, Preschool; D003365:Costs and Cost Analysis; D003550:Cystic Fibrosis / Q000150:complications / Q000191:economics*; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008137:Longitudinal Studies; D008297:Male; D008329:Managed Care Programs / Q000706:statistics & numerical data*; D008875:Middle Aged; D011552:Pseudomonas Infections / Q000209:etiology / Q000517:prevention & control*; D012189:Retrospective Studies; D014031:Tobramycin / Q000008:administration & dosage* / Q000191:economics / Q000627:therapeutic use; D055815:Young Adult
chemical_list: D000900:Anti-Bacterial Agents; D014031:Tobramycin