title: Clinical use of tobramycin inhalation solution (TOBI®) shows sustained improvement in FEV1 in cystic fibrosis.
abstract: OBJECTIVE
  Tobramycin inhalation solution (TIS; TOBI®) has improved forced expiratory volume in 1 sec (FEV1 ) in cystic fibrosis (CF) trials. Using data from the Epidemiologic Study of CF (ESCF), we assessed the change in level and trend of FEV1 % predicted (pred) over a 2-year period associated with initiation of TIS during routine clinical practice.
  
  
  METHODS
  Patients age 8-38 years and in ESCF for ≥2 years before treatment with TIS as a chronic therapy were selected if they remained on therapy for 2 years, defined as being on TIS for at least 3 months per year (C-TIS group). Comparator intervals age 8-38 years used TIS <10% of the time. For each interval, we estimated the level and trend (rate of decline) in FEV1 % pred before and after the index using a piecewise linear mixed-effects model adjusted for potential confounders.
  
  
  RESULTS
  During the 2-year pre-index period the C-TIS group (n = 2,534) had a more rapid decline in FEV1 (-2.49% vs. -1.39% pred/year) and a lower FEV1 at index (62.6% vs. 74.7% pred) than the comparator group (N = 17,656 intervals). After starting chronic TIS, the FEV1 trend line over the 2-year post-index period was higher, but the comparator group's FEV1 was essentially unchanged (difference 2.22, P < 0.001). Change in slope was not different between groups (0.06, P = 0.82).
  
  
  CONCLUSIONS
  Initiating chronic TIS therapy in the routine clinical care of patients with CF was associated with improvement in FEV1 % pred but no change in rate of decline, which means that this benefit was sustained over the 2 years studied.
authors.affiliation: Department of Pediatrics, Case Western Reserve University School of Medicine, Rainbow Babies and Children's Hospital, Cleveland, Ohio.
authors.forename: Michael W
authors.initials: MW
authors.lastname: Konstan
authors.forename: Jeffrey S
authors.initials: JS
authors.lastname: Wagener
authors.forename: David J
authors.initials: DJ
authors.lastname: Pasta
authors.forename: Stefanie J
authors.initials: SJ
authors.lastname: Millar
authors.forename: Wayne J
authors.initials: WJ
authors.lastname: Morgan
mesh_terms: D000280:Administration, Inhalation; D000293:Adolescent; D000328:Adult; D000900:Anti-Bacterial Agents / Q000008:administration & dosage*; D002648:Child; D003550:Cystic Fibrosis / Q000188:drug therapy* / Q000503:physiopathology; D005260:Female; D005541:Forced Expiratory Volume / Q000502:physiology; D006801:Humans; D008297:Male; D014031:Tobramycin / Q000008:administration & dosage*; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D000900:Anti-Bacterial Agents; D014031:Tobramycin
keywords: cystic fibrosis; epidemiology; pulmonary function; tobramycin inhalation solution
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