OBJECTIVES: This study evaluated qualitative equivalence between paper and electronic tablet versions of 12 PRO instruments used in RA studies: Pain Visual Analogue Scale (VAS), Global Disease VAS, HAQ-DI, MOS Sleep Scale, WPAI:RA, Rheumatology Attitudes Index, Sexual Impairment due to RA, Perception of Ultrasound in Management of RA, TSQM, FACIT–Fatigue Scale, Compliance Questionnaire Rheumatology, and RA-WIS.  The usability of two tablets was also evaluated. METHODS: A cross-sectional qualitative study was conducted involving cognitive and usability interviews with US patients diagnosed with RA. Twelve instruments were administered on a TrialSlate™ tablet (Sahara a230T™ or Acer 510P™) and paper, with each participant completing a subset of instruments on one tablet and paper. Participants were randomized to one of four instrument subgroups, tablet type, and order of mode completion.  RESULTS: Mean age of the sample (N=40) was 57 years, (range 24-86), 45% over 60 years; 82.5% were female; 87.5% were white; 37.5% were retired; 37.5% had completed secondary school. All participants understood the items and responses as intended across instruments and platforms. Most participants considered the layouts similar and reported the devices easy to use and navigate. Participants reported the Acer touchscreen or stylus with Sahara easier to use than holding a writing utensil. The majority preferred the tablet over paper.  Minor usability issues included glare on the Sahara and small font size on the Acer. Differences in response between modes attributed to differences in format were noted by 10 Acer participants and 10 Sahara participants.  CONCLUSIONS: The study demonstrated qualitative equivalence between paper and electronic versions of 12 PRO instruments as mode did not influence how most participants interpreted the questions and their response selections, with only minor usability issues reported.  This study also supported usability of both tablet devices with an RA population which preferred electronic over paper.