title: Electronic monitoring reveals highly variable adherence patterns in patients prescribed ivacaftor.
abstract: BACKGROUND
  Previous studies of CF treatments have shown suboptimal adherence, though little has been reported regarding adherence patterns to ivacaftor. Electronic monitoring (EM) of adherence is considered a gold standard of measurement.
  
  
  METHODS
  Adherence rates by EM were prospectively obtained and patterns over time were analyzed. EM-derived adherence rates were compared to pharmacy refill history and self-report.
  
  
  RESULTS
  12 subjects (age 6-48 years; CFTR-G551D mutation) previously prescribed ivacaftor were monitored for a mean of 118 days. Overall adherence by EM was 61% (SD=28%) and decreased over time. Median duration between doses was 16.9 hours (IQR 13.9-24.1 hours) and increased over time. There was no correlation between EM-derived adherence and either refill history (84%, r=0.26, p=0.42) or self-report (100%, r=0.40, p=0.22).
  
  
  CONCLUSIONS
  Despite the promising nature of ivacaftor, our data suggest adherence rates are suboptimal and comparable to other prescribed CF therapies, and more commonly used assessments of adherence may be unreliable.
authors.affiliation: Division of Pulmonary Medicine, Cincinnati Children's Hospital Medical Center (CCHMC), 3333 Burnet Ave, Cincinnati, OH 45202, USA. Electronic address: christopher.siracusa@cchmc.org.
authors.forename: Christopher M
authors.initials: CM
authors.lastname: Siracusa
authors.affiliation: Division of Behavioral Medicine and Clinical Psychology, CCHMC, 3333 Burnet Ave, Cincinnati, OH 45202, USA. Electronic address: jamie.ryan@cchmc.org.
authors.forename: Jamie
authors.initials: J
authors.lastname: Ryan
authors.affiliation: Division of Pulmonary Medicine, Cincinnati Children's Hospital Medical Center (CCHMC), 3333 Burnet Ave, Cincinnati, OH 45202, USA. Electronic address: lisa.burns2@cchmc.org.
authors.forename: Lisa
authors.initials: L
authors.lastname: Burns
authors.affiliation: Division of Biostatistics and Epidemiology, CCHMC, 3333 Burnet Ave, Cincinnati, OH 45202, USA. Electronic address: yu.wang@cchmc.org.
authors.forename: Yu
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Division of Biostatistics and Epidemiology, CCHMC, 3333 Burnet Ave, Cincinnati, OH 45202, USA. Electronic address: nanhua.zhang@cchmc.org.
authors.forename: Nanhua
authors.initials: N
authors.lastname: Zhang
authors.affiliation: Division of Pulmonary Medicine, Cincinnati Children's Hospital Medical Center (CCHMC), 3333 Burnet Ave, Cincinnati, OH 45202, USA. Electronic address: john.clancy@cchmc.org.
authors.forename: John P
authors.initials: JP
authors.lastname: Clancy
authors.affiliation: Division of Behavioral Medicine and Clinical Psychology, CCHMC, 3333 Burnet Ave, Cincinnati, OH 45202, USA. Electronic address: dennis.drotar@cchmc.org.
authors.forename: Dennis
authors.initials: D
authors.lastname: Drotar
mesh_terms: D000293:Adolescent; D000328:Adult; D000627:Aminophenols / Q000627:therapeutic use*; D002648:Child; D016303:Clinical Pharmacy Information Systems; D003550:Cystic Fibrosis / Q000188:drug therapy*; D019005:Cystic Fibrosis Transmembrane Conductance Regulator; D016903:Drug Monitoring / Q000379:methods*; D011307:Drug Prescriptions / Q000706:statistics & numerical data*; D001330:Electronic Data Processing / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D015363:Quinolones / Q000627:therapeutic use*; D055815:Young Adult
chemical_list: D000627:Aminophenols; D015363:Quinolones; D019005:Cystic Fibrosis Transmembrane Conductance Regulator; C545203:ivacaftor
keywords: Adherence; Pediatric; Potentiator