Objectives: To explore the concept of work instability (WI), a state in which the consequences of a mismatch between an individual's functional abilities and the demands of his or her job could threaten continuing employment if not resolved, in people with rheumatoid arthritis (RA). To develop the Work Instability Scale (WIS).
Methods: WI in people with RA was explored through qualitative interviews, which were then used to generate items for the WIS.
Results: Through Rasch analysis and validation against a gold standard of expert vocational assessment, a short 23-item, self administered, RA WIS was developed.
Conclusion: The WIS can be scored in 3 bands indicating low, medium, and high risk of work disability.