Development and psychometric properties of a joint protection self-efficacy scale

Abstract

Introduction. 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.

Key words::

• Joint protection
• occupational therapy
• Rasch analysis
• rehabilitation
• rheumatoid arthritis
• self-efficacy
• validation

Acknowledgements

The authors would like to thank Prof. Alan Tennant (Leeds, UK) for his helpful comments in an earlier draft of this paper and Mrs Leanne Pobjoy (University Hospital Zurich) for her support in preparing the manuscript.

Competing interests

None.

Funding

None.

Notes