title: The development and initial psychometric evaluation of a measure assessing adherence to prescribed exercise: the Exercise Adherence Rating Scale (EARS).
abstract: OBJECTIVE
  There is no gold standard for measuring adherence to prescribed home exercise. Self-report diaries are commonly used however lack of standardisation, inaccurate recall and self-presentation bias limit their validity. A valid and reliable tool to assess exercise adherence behaviour is required. Consequently, this article reports the development and psychometric evaluation of the Exercise Adherence Rating Scale (EARS).
  
  
  METHODS
  Development of a questionnaire.
  
  
  METHODS
  Secondary care in physiotherapy departments of three hospitals.
  
  
  METHODS
  A focus group consisting of 8 patients with chronic low back pain (CLBP) and 2 physiotherapists was conducted to generate qualitative data. Following on from this, a convenience sample of 224 people with CLBP completed the initial 16-item EARS for purposes of subsequent validity and reliability analyses.
  
  
  METHODS
  Construct validity was explored using exploratory factor analysis and item response theory. Test-retest reliability was assessed 3 weeks later in a sub-sample of patients.
  
  
  RESULTS
  An item pool consisting of 6 items was found suitable for factor analysis. Examination of the scale structure of these 6 items revealed a one factor solution explaining a total of 71% of the variance in adherence to exercise. The six items formed a unidimensional scale that showed good measurement properties, including acceptable internal consistency and high test-retest reliability.
  
  
  CONCLUSIONS
  The EARS enables the measurement of adherence to prescribed home exercise. This may facilitate the evaluation of interventions promoting self-management for both the prevention and treatment of chronic conditions.
authors.affiliation: Division of Health and Social Care Research, Faculty of Life Sciences & Medicine, King's College London, 5th Floor Addison House, Guy's Campus, London SE1 1UL, United Kingdom.
authors.forename: Naomi A
authors.initials: NA
authors.lastname: Newman-Beinart
authors.affiliation: Department of Psychology (at Guy's), IoPPN, King's College London, 5th Floor Bermondsey Wing, Guy's Campus, London SE1 9RT, United Kingdom.
authors.forename: Sam
authors.initials: S
authors.lastname: Norton
authors.affiliation: Department of Psychology (at Guy's), IoPPN, King's College London, 5th Floor Bermondsey Wing, Guy's Campus, London SE1 9RT, United Kingdom.
authors.forename: Dominic
authors.initials: D
authors.lastname: Dowling
authors.affiliation: Department of Psychology (at Guy's), IoPPN, King's College London, 5th Floor Bermondsey Wing, Guy's Campus, London SE1 9RT, United Kingdom.
authors.forename: Dimitri
authors.initials: D
authors.lastname: Gavriloff
authors.affiliation: Department of Psychology (at Guy's), IoPPN, King's College London, 5th Floor Bermondsey Wing, Guy's Campus, London SE1 9RT, United Kingdom.
authors.forename: Chiara
authors.initials: C
authors.lastname: Vari
authors.affiliation: Department of Psychology (at Guy's), IoPPN, King's College London, 5th Floor Bermondsey Wing, Guy's Campus, London SE1 9RT, United Kingdom.
authors.forename: John A
authors.initials: JA
authors.lastname: Weinman
authors.affiliation: Division of Health and Social Care Research, Faculty of Life Sciences & Medicine, King's College London, 5th Floor Addison House, Guy's Campus, London SE1 1UL, United Kingdom; Department of Psychology (at Guy's), IoPPN, King's College London, 5th Floor Bermondsey Wing, Guy's Campus, London SE1 9RT, United Kingdom. Electronic address: emma.l.godfrey@kcl.ac.uk.
authors.forename: Emma L
authors.initials: EL
authors.lastname: Godfrey
mesh_terms: D000328:Adult; D000368:Aged; D005081:Exercise Therapy / Q000523:psychology*; D005163:Factor Analysis, Statistical; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010349:Patient Compliance / Q000523:psychology*; D026741:Physical Therapy Modalities / Q000592:standards*; D011594:Psychometrics; D015203:Reproducibility of Results; D011795:Surveys and Questionnaires; D055815:Young Adult
keywords: Adherence; Assessment; Chronic illness; Compliance; Measurement; Prescribed exercise