A 5 item version of the Workplace Activity Limitation Scale successfully identifies impaired work productivity in rheumatoid arthritis patients: A split-sample factor analysis approach.

Background: There is a growing interest in studying the effects of arthritis on a person's work productivity using a growing variety of outcome indicators.

Objectives: 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.

Methods: A cross-sectional study involving 277 RA patients was conducted.