Differences in Longitudinal Disease and Treatment Characteristics of Patients with Rheumatoid Arthritis Replying and Not Replying to a Postal Questionnaire. Experience from a Biologics Register in Southern Sweden.
OBJECTIVE: Studies on patients not answering postal questionnaires are scarce. We assessed the demographics and longitudinal disease and treatment characteristics of patients with rheumatoid arthritis (RA) in a Swedish biologics register who replied and who did not reply to a postal questionnaire. METHODS: In the South Swedish Arthritis Treatment Group register, we have detailed disease severity c
