title: Assessing usability of the "Adherence Starts with Knowledge 20" (ASK-20) questionnaire for Japanese adults with bronchial asthma receiving inhaled corticosteroids long term.
abstract: BACKGROUND
  Maintaining high treatment adherence levels is critical for effective management of chronic diseases. The Adherence Starts with Knowledge 20 (ASK-20) questionnaire is the only linguistically validated patient-reported treatment adherence tool available in Japan. We conducted additional analyses on ASK-20 data from Japanese adults with asthma.
  
  
  METHODS
  This was a prospective, non-interventional, single-visit, multi-centre study in Japanese adults (n = 300) with asthma receiving long-term treatment with inhaled corticosteroids (ICS) or ICS/long-acting beta-agonists. We tested the reliability, validity and the relationship between different adherence conditions and ASK-20 score. At one centre, ICS adherence prescription rate was calculated retrospectively based on 2-year percentage ICS adherence data contained within medical records.
  
  
  RESULTS
  The ASK-20 had good internal consistency reliability (Cronbach's alpha = 0.76; n = 290). Discriminant validity was demonstrated with significant correlations between the percentage ICS adherence rates and both the mean ASK-20 total score and mean total barrier count (TBC) (r = -0.51 and -0.58, p < 0.001; n = 111). The ASK-20 total score discriminated between subjects with good and poor adherence measured by patients' reported questionnaire and between those of high and low percentage ICS adherence rates. All other factors that possibly affect adherence were correlated with the mean ASK-20 total score and mean TBC in addition to the number of medicines taken every day.
  
  
  CONCLUSIONS
  The Japanese ASK-20 is a reliable tool for assessing possible medication adherence barriers and adherence behaviour in Japanese adults with asthma. Furthermore, our results are comparable with those obtained using the ASK-20 in the United States.
authors.affiliation: Department of Respiratory Medicine, Juntendo Tokyo Koto Geriatric Medical Center, Tokyo, Japan. Electronic address: atsuta@juntendo.ac.jp.
authors.forename: Ryo
authors.initials: R
authors.lastname: Atsuta
authors.affiliation: Department of Allergy and Respiratory Medicine, The Fraternity Memorial Hospital, Tokyo, Japan.
authors.forename: Yasuo
authors.initials: Y
authors.lastname: To
authors.affiliation: Department of Respiratory Medicine, Toho University Omori Medical Center, Tokyo, Japan.
authors.forename: Susumu
authors.initials: S
authors.lastname: Sakamoto
authors.affiliation: Medical Affairs Respiratory Department, GlaxoSmithKline KK, Tokyo, Japan.
authors.forename: Isao
authors.initials: I
authors.lastname: Mukai
authors.affiliation: Biomedical Data Sciences Department, GlaxoSmithKline KK, Tokyo, Japan.
authors.forename: Akihiro
authors.initials: A
authors.lastname: Kobayashi
authors.affiliation: Department of Respiratory Medicine, Toho University Omori Medical Center, Tokyo, Japan.
authors.forename: Arisa
authors.initials: A
authors.lastname: Kinoshita
authors.affiliation: Department of Respiratory Medicine, Juntendo University Faculty of Medicine, Tokyo, Japan.
authors.forename: Kazuhisa
authors.initials: K
authors.lastname: Takahashi
mesh_terms: D000280:Administration, Inhalation; D000305:Adrenal Cortex Hormones / Q000008:administration & dosage*; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D018927:Anti-Asthmatic Agents / Q000008:administration & dosage*; D001249:Asthma / Q000175:diagnosis / Q000188:drug therapy* / Q000453:epidemiology*; D004359:Drug Therapy, Combination; D005260:Female; D019538:Health Care Surveys; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008297:Male; D055118:Medication Adherence; D008875:Middle Aged; D015203:Reproducibility of Results; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D000305:Adrenal Cortex Hormones; D018927:Anti-Asthmatic Agents
keywords: ASK-20; Adherence; Asthma; Reliability; Validity