title: Patient-reported side effects, concerns and adherence to corticosteroid treatment for asthma, and comparison with physician estimates of side-effect prevalence: a UK-wide, cross-sectional study.
abstract: BACKGROUND
  Non-adherence to corticosteroid treatment has been shown to reduce treatment efficacy, thus compromising asthma control.
  
  
  OBJECTIVE
  To examine the experiences of treatment side effects, treatment concerns and adherence to inhaled (ICS) and oral corticosteroids (OCS) among people with asthma and to identify the degree of concordance between clinician estimates of side effects and the prevalence reported by patients.
  
  
  METHODS
  Asthma UK members were sent validated questionnaires assessing treatment concerns, experiences of side effects and adherence. Questionnaires measuring clinicians' estimates of the prevalence of corticosteroid side effects were completed online.
  
  
  RESULTS
  Completed questionnaires were returned by 1,524 people taking ICS, 233 taking OCS and 244 clinicians (67% of clinicians were primary care nurses). Among people with asthma, 64% of those taking ICS and 88% of those taking OCS reported ⩾ 1 side effect. People reporting high adherence to ICS (t = -3.09, P<0.005) and those reporting low adherence to OCS (t = 1.86, P < 0.05; one-tailed test) reported more side effects. There was a disparity between clinicians' estimates of the frequency of side effects and the frequency reported by people with asthma: e.g., although 46% of people taking ICS reported sore throat, clinicians estimated that this figure would be 10%. Patients who reported side effects had stronger concerns about both ICS (r = 0.46, P < 0.0001) and OCS (r = 0.50, P < 0.0001). Concerns about corticosteroids were associated with low adherence to ICS (t = 6.90, P < 0.0001) and OCS (t = 1.71; P < 0.05; one-tailed test).
  
  
  CONCLUSIONS
  An unexpectedly large proportion of people with asthma experienced side effects and had strong concerns about their treatment, which compromised adherence. These findings have implications for the design of interventions to optimise asthma control through improved adherence.
authors.affiliation: Centre for Behavioural Medicine, UCL School of Pharmacy, London, UK.
authors.forename: Vanessa
authors.initials: V
authors.lastname: Cooper
authors.affiliation: Asthma UK, London, UK.
authors.forename: Leanne
authors.initials: L
authors.lastname: Metcalf
authors.affiliation: Asthma UK, London, UK.
authors.forename: Jenny
authors.initials: J
authors.lastname: Versnel
authors.affiliation: Education for Health, London, UK.
authors.forename: Jane
authors.initials: J
authors.lastname: Upton
authors.affiliation: Education for Health, London, UK.
authors.forename: Samantha
authors.initials: S
authors.lastname: Walker
authors.affiliation: Centre for Behavioural Medicine, UCL School of Pharmacy, London, UK.
authors.forename: Rob
authors.initials: R
authors.lastname: Horne
mesh_terms: D000280:Administration, Inhalation; D000284:Administration, Oral; D000305:Adrenal Cortex Hormones / Q000009:adverse effects*; D000328:Adult; D000368:Aged; D001249:Asthma / Q000188:drug therapy*; D002180:Candidiasis, Oral / Q000139:chemically induced / Q000453:epidemiology; D003288:Contusions / Q000139:chemically induced / Q000453:epidemiology; D003430:Cross-Sectional Studies; D064420:Drug-Related Side Effects and Adverse Reactions / Q000453:epidemiology* / Q000209:etiology; D005260:Female; D006801:Humans; D008297:Male; D055118:Medication Adherence; D001523:Mental Disorders / Q000139:chemically induced / Q000453:epidemiology; D008875:Middle Aged; D010612:Pharyngitis / Q000139:chemically induced / Q000453:epidemiology; D058007:Physicians, Primary Care; D015995:Prevalence; D059017:Primary Care Nursing; D011320:Primary Health Care; D057566:Self Report; D009057:Stomatognathic Diseases / Q000139:chemically induced / Q000453:epidemiology; D011795:Surveys and Questionnaires; D006113:United Kingdom; D015430:Weight Gain
chemical_list: D000305:Adrenal Cortex Hormones