title: Accurate assessment of adherence: self-report and clinician report vs electronic monitoring of nebulizers.
abstract: BACKGROUND
  People with cystic fibrosis have a high treatment burden. While uncertainty remains about individual patient level of adherence to medication, treatment regimens are difficult to tailor, and interventions are difficult to evaluate. Self- and clinician-reported measures are routinely used despite criticism that they overestimate adherence. This study assessed agreement between rates of adherence to prescribed nebulizer treatments when measured by self-report, clinician report, and electronic monitoring suitable for long-term use.
  
  
  METHODS
  Seventy-eight adults with cystic fibrosis were questioned about their adherence to prescribed nebulizer treatments over the previous 3 months. Self-report was compared with clinician report and stored adherence data downloaded from the I-Neb nebulizer system. Adherence measures were expressed as a percentage of the prescribed regimen, bias was estimated by the paired difference in mean (95% CI) patient and clinician reported and actual adherence. Agreement between adherence measures was calculated using intraclass correlation coefficients (95% CI), and disagreements for individuals were displayed using Bland-Altman plots.
  
  
  RESULTS
  Patient-identified prescriptions matched the medical record prescription. Median self-reported adherence was 80% (interquartile range, 60%-95%), whereas median adherence measured by nebulizer download was 36% (interquartile range, 5%-84.5%). Nine participants overmedicated and underreported adherence. Median clinician report ranged from 50% to 60%, depending on profession. Extensive discrepancies between self-report and clinician report compared with nebulizer download were identified for individuals.
  
  
  CONCLUSIONS
  Self- and clinician-reporting of adherence does not provide accurate measurement of adherence when compared with electronic monitoring. Using inaccurate measures has implications for treatment burden, clinician prescribing practices, cost, and accuracy of trial data.
authors.affiliation: York Adult Cystic Fibrosis Unit, York Teaching Hospital Foundation NHS Trust, York Hospital, York. Electronic address: traceydaniels1@nhs.net.
authors.forename: Tracey
authors.initials: T
authors.lastname: Daniels
authors.affiliation: School of Public Health and Clinical Sciences, University of Central Lancashire, Preston.
authors.forename: Lynne
authors.initials: L
authors.lastname: Goodacre
authors.affiliation: School of Public Health and Clinical Sciences, University of Central Lancashire, Preston.
authors.forename: Chris
authors.initials: C
authors.lastname: Sutton
authors.affiliation: Leeds Regional Adult Cystic Fibrosis Unit, The Leeds Teaching Hospitals NHS Trust, St James's Hospital, Leeds, England.
authors.forename: Kim
authors.initials: K
authors.lastname: Pollard
authors.affiliation: Leeds Regional Adult Cystic Fibrosis Unit, The Leeds Teaching Hospitals NHS Trust, St James's Hospital, Leeds, England.
authors.forename: Steven
authors.initials: S
authors.lastname: Conway
authors.affiliation: Leeds Regional Adult Cystic Fibrosis Unit, The Leeds Teaching Hospitals NHS Trust, St James's Hospital, Leeds, England.
authors.forename: Daniel
authors.initials: D
authors.lastname: Peckham
mesh_terms: D000328:Adult; D003550:Cystic Fibrosis / Q000188:drug therapy*; D004581:Electronics; D005260:Female; D006801:Humans; D008297:Male; D055118:Medication Adherence; D009330:Nebulizers and Vaporizers / Q000706:statistics & numerical data*; D057566:Self Report; D055815:Young Adult