Development and psychometric properties of a joint protection self-efficacy scale.
BACKGROUND
Self-efficacy is one of the most powerful determinants of behaviour change. To increase effectiveness of joint protection (JP) education, it may be important to address perceptions of JP self-efficacy directly. The aim of this study was to develop a scale to measure JP self-efficacy (JP-SES) in people with rheumatoid arthritis (RA).


METHODS
Instrument development included item generation, construct validity, and reliability testing. Rasch analysis was applied to determine construct validity and the revised JP-SES was tested again to confirm validity and establish test-retest reliability and internal consistency.


RESULTS
A total of 46 items were generated by literature review, occupational therapists, and people with RA. After semi-structured interviews and field-testing with RA participants, a 26-item questionnaire draft was constructed and tested. Rasch analysis to determine construct validity reduced the JP-SES to 13 items with good overall fit values. Rasch analysis of confirmatory validity resulted in a final 10-item version of the JP-SES. Test-retest results supported the validity of the scale, with high internal consistency (α = 0.92) and good test-retest reliability (r(s) = 0.79; p < 0.001).


CONCLUSIONS
The JP-SES is a valid and reliable scale to assess perceived ability of people with RA to apply JP methods. The JP-SES could help stimulate the use of efficacy-enhancing methods in JP education.
Niedermann
Karin
K
Department of Rheumatology and Institute of Physical Medicine, University Hospital Zurich, Switzerland. karin.niedermann@usz.ch
Forster
Adrian
A
Ciurea
Adrian
A
Hammond
Alison
A
Uebelhart
Daniel
D
de Bie
Rob
R
D000328:Adult; D000368:Aged; D001172:Arthritis, Rheumatoid / Q000503:physiopathology* / Q000523:psychology*; D004185:Disability Evaluation; D005260:Female; D005858:Germany; D007722:Health Knowledge, Attitudes, Practice; D006801:Humans; D007596:Joints / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D009788:Occupational Therapy / Q000379:methods*; D011594:Psychometrics / Q000379:methods*; D020377:Self Efficacy; D011795:Surveys and Questionnaires