title: Development and validation of a self-efficacy scale for use in British patients with rheumatoid arthritis (RASE).
abstract: OBJECTIVE
  Current arthritis self-efficacy scales have attracted some criticism. Therefore, the aim of this study was to develop and validate a measure of self-efficacy for use in British rheumatoid arthritis patients [Rheumatoid Arthritis Self-efficacy (RASE) scale].
  
  
  METHODS
  Phase I: item generation of self-management strategies by rheumatology professionals and patients to create a pilot RASE. Phase II: examination of the internal structure (n=88) using correlation coefficients and principal component analysis (PCA) to create the final RASE. Phase III: reliability in 23 patients. Phase IV: comprehension, construct validity and sensitivity to change in 48 rheumatoid arthritis patients undergoing a self-management programme, using correlation coefficients, PCA and inter-item correlation.
  
  
  RESULTS
  Phase I: of 166 self-management items generated, 100 commonly cited items were selected for the pilot RASE. Phase II: using a correlation matrix and PCA, a 28-item RASE was created. Phase III: good 4-week reliability was seen (r=0.889, P<0.001). Phase IV: the final RASE was shown to be independent of mood, disease status and disability and weakly associated with other self-efficacy scales (r=0.313, P<0.05). The RASE was sensitive to change following an education programme (+5.167, P<0.025), and was associated with behaviour initiation (r=0.35, P<0.01).
  
  
  CONCLUSIONS
  Careful construction means that the RASE examines beliefs in potential ability to perform tasks, rather than actual ability, performance or outcome expectancy. It shows good face validity and reliability, plus reasonable construct validity and sensitivity. Further studies are needed to support the validation of this new scale.
authors.affiliation: Rheumatology Unit, University of Bristol Division of Medicine, Bristol Royal Infirmary, Bristol, UK.
authors.forename: S
authors.initials: S
authors.lastname: Hewlett
authors.forename: Z
authors.initials: Z
authors.lastname: Cockshott
authors.forename: J
authors.initials: J
authors.lastname: Kirwan
authors.forename: J
authors.initials: J
authors.lastname: Barrett
authors.forename: J
authors.initials: J
authors.lastname: Stamp
authors.forename: I
authors.initials: I
authors.lastname: Haslock
mesh_terms: D000328:Adult; D000368:Aged; D001172:Arthritis, Rheumatoid / Q000523:psychology*; D004185:Disability Evaluation; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012648:Self Care; D020377:Self Efficacy; D012680:Sensitivity and Specificity; D011795:Surveys and Questionnaires; D006113:United Kingdom