Linguistic Validation into 20 Languages and Content Validity of the Rheumatoid Arthritis-Specific Work Productivity and Activity Impairment Questionnaire

Background Impairments in work productivity and daily activities contribute to the burden of rheumatoid arthritis (RA). It is thus essential to use an instrument assessing both work and daily activity impairments when studying the full impact of RA on individuals. The Work Productivity and Activity Impairment (WPAI) questionnaire is such an instrument.