From the epidemiological point of view, RABBIT is a prospective cohort study. Patients with rheumatoid arthritis are enrolled in RABBIT when they start a new therapy either with a biologic or a non-biologic DMARD. They are followed up for a certain period of time (a minimum of five years), regardless of the further course of therapy.

Patients and their rheumatologists complete questionnaires during regular doctor visits at study enrolment, after three months, and then every six months.

Physicians’ questionnaires contain queries on the current anti-rheumatic therapy, previous treatments and respective reasons for their discontinuations, on adverse events and disease activity. Patients’ questionnaires comprise data on disease activity, pain and fatigue severity, as well as on smoking, occupation and (premature) pension. Specific disease dimensions of rheumatoid arthritis are assessed by means of standardized instruments, i.e. health-related quality of life by the short form health survey SF36, and functional status by the German Funktionsfragebogen Hannover (FFbH, which can be transformed into the HAQ).

RABBIT is a non-interventional observational study, which means that there is no influence on any treatment decision. The type of the treatment administered, and the conduct of individual therapy including dosages is determined only by the treating physician, in agreement with the patient.

It is very important that patients do not cancel the observation prematurely, even upon termination or change of therapy. Results are the more reliable the more patients are observed over at least five, better ten years. Therefore, the RABBIT team supports rheumatologists by sending reminders of future visits and by contacting patients who are no longer with the original physician.