There is a growing interest in studying the effects of arthritis on a person's work productivity using a growing variety of outcome indicators.
To develop a valid and reliable shortened version of the Workplace Activity Limitation Scale 12 (WALS‐12) for assessing work productivity limitations in rheumatoid arthritis (RA) patients.
A cross‐sectional study involving 277 RA patients was conducted. An exploratory factor analysis on WALS‐12 was used for item reduction on the first sample. Then confirmatory factor analysis (CFA) was run to establish the best fit indices of the reduced version. On the second sample, CFA and linear discriminant analysis were performed to assess the diagnostic performance and discriminant ability of the reduced form. A Bland–Altman method was used to find the agreement between the WALS‐12 and the reduced one.
The WALS‐12 was reduced to 5 items. The Cronbach
WALS‐5 is a valid and reliable tool to assess the work productivity limitations in RA patients.