title: A method to assess adherence in inhaler use through analysis of acoustic recordings of inhaler events.
abstract: BACKGROUND
  Poor adherence to inhaler use can be due to poor temporal and/or technique adherence. Up until now there has been no way of reliably tracking both these factors in everyday inhaler use.
  
  
  OBJECTIVE
  This paper introduces a device developed to create time stamped acoustic recordings of an individual's inhaler use, in which empirical evidence of temporal and technique adherence in inhaler use can be monitored over time. The correlation between clinical outcomes and adherence, as determined by this device, was compared for temporal adherence alone and combined temporal and technique adherence.
  
  
  RESULTS
  The technology was validated by showing that the doses taken matched the number of audio recordings (r2 = 0.94, p<0.01). To demonstrate that audio analysis of inhaler use gives objective information, in vitro studies were performed. These showed that acoustic profiles of inhalations correlated with the peak inspiratory flow rate (r2 = 0.97, p<0.01), and that the acoustic energy of exhalations into the inhaler was related to the amount of drug removed. Despite training, 16% of participants exhaled into the mouthpiece after priming, in >20% of their inhaler events. Repeated training reduced this to 7% of participants (p = 0.03). When time of use was considered, there was no evidence of a relationship between adherence and changes in AQLQ (r2 = 0.2) or PEFR (r2 = 0.2). Combining time and technique the rate of adherence was related to changes in AQLQ (r2 = 0.53, p = 0.01) and PEFR (r2 = 0.29, p = 0.01).
  
  
  CONCLUSIONS
  This study presents a novel method to objectively assess how errors in both time and technique of inhaler use impact on clinical outcomes.
  
  
  BACKGROUND
  EudraCT 2011-004149-42.
authors.affiliation: Trinity Centre for Bioengineering, Trinity College Dublin, Dublin, Ireland.
authors.forename: Shona
authors.initials: S
authors.lastname: D'Arcy
authors.affiliation: The Department of Medicine, Royal College of Surgeons in Ireland, Dublin, Ireland.
authors.forename: Elaine
authors.initials: E
authors.lastname: MacHale
authors.affiliation: The Department of Medicine, Royal College of Surgeons in Ireland, Dublin, Ireland.
authors.forename: Jansen
authors.initials: J
authors.lastname: Seheult
authors.affiliation: Trinity Centre for Bioengineering, Trinity College Dublin, Dublin, Ireland.
authors.forename: Martin S
authors.initials: MS
authors.lastname: Holmes
authors.affiliation: Trinity Centre for Bioengineering, Trinity College Dublin, Dublin, Ireland.
authors.forename: Cian
authors.initials: C
authors.lastname: Hughes
authors.affiliation: The Department of Medicine, Royal College of Surgeons in Ireland, Dublin, Ireland.
authors.forename: Imran
authors.initials: I
authors.lastname: Sulaiman
authors.affiliation: Clinical Research Centre, Royal College of Surgeons in Ireland, Dublin, Ireland.
authors.forename: Deirdre
authors.initials: D
authors.lastname: Hyland
authors.affiliation: The Department of Medicine, Royal College of Surgeons in Ireland, Dublin, Ireland.
authors.forename: Conor
authors.initials: C
authors.lastname: O'Reilly
authors.affiliation: The Department of Medicine, Royal College of Surgeons in Ireland, Dublin, Ireland.
authors.forename: Senan
authors.initials: S
authors.lastname: Glynn
authors.affiliation: The Department of Medicine, Royal College of Surgeons in Ireland, Dublin, Ireland.
authors.forename: Thekra
authors.initials: T
authors.lastname: Al-Zaabi
authors.affiliation: Dublin Centre for Clinical Research, Dublin, Ireland.
authors.forename: John
authors.initials: J
authors.lastname: McCourt
authors.affiliation: Vitalograph, Ennis, Co Clare, Ireland.
authors.forename: Terence
authors.initials: T
authors.lastname: Taylor
authors.affiliation: Vitalograph, Ennis, Co Clare, Ireland.
authors.forename: Frank
authors.initials: F
authors.lastname: Keane
authors.affiliation: Trinity Centre for Bioengineering, Trinity College Dublin, Dublin, Ireland.
authors.forename: Isabelle
authors.initials: I
authors.lastname: Killane
authors.affiliation: Trinity Centre for Bioengineering, Trinity College Dublin, Dublin, Ireland.
authors.forename: Richard B
authors.initials: RB
authors.lastname: Reilly
authors.affiliation: The Department of Medicine, Royal College of Surgeons in Ireland, Dublin, Ireland; Clinical Research Centre, Royal College of Surgeons in Ireland, Dublin, Ireland.
authors.forename: Richard W
authors.initials: RW
authors.lastname: Costello
mesh_terms: D000162:Acoustics / Q000295:instrumentation*; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001330:Electronic Data Processing; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009330:Nebulizers and Vaporizers / Q000706:statistics & numerical data*; D010349:Patient Compliance; D013997:Time Factors; D055815:Young Adult