[RABBIT-SpA: a new disease register for axial spondyloarthritis and psoriatic arthritis]

BACKGROUND: The treatment of axial spondyloarthritis (axSpA) and psoriatic arthritis (PsA) has changed enormously in recent years due to market authorization of a number of new biologicals with different modes of action and the increasing use of biosimilars. Real-world data on long-term safety and efficacy under routine daily conditions is not yet sufficient. Therefore, the German Rheumatism Research Center has initiated a new cohort study covering axSpA and PsA. OBJECTIVE: Presentation of initial results from the new register RABBIT-SpA, which was started in May 2017. MATERIAL AND METHODS: This is a prospective longitudinal cohort study with a similar study design to the German biologics register RABBIT. Patients can be included at the start of a new treatment either in the so-called index drug group or in the comparison group (conventional systemic treatment, including non-steroidal anti-inflammatory drugs, NSAID). Follow-up per patient should be at least 5 years and preferably 10 years. The RABBIT-SpA uses a web-based documentation system. RESULTS: Up to mid-December 2018 a total of 514 axSpA patients had been documented in RABBIT-SpA, 410 with an index drug and 104 with conventional treatment. There are differences between these treatment groups, e. g. in the duration of the disease and in parameters of disease activity. It is also noticeable that in axSpA patients, approximately 5 years lie between the onset of the symptoms and confirmation of the diagnosis. Of the 355 PsA patients, 265 were included with an index drug and 90 with conventional treatment. Of the PsA patients 86% have a dominant peripheral manifestation. The average number of pressure tender joints is 8 and the average number of swollen joints is 4. CONCLUSION: The online register RABBIT-SpA is well-received by the participating rheumatological institutions. The electronic recording of patient data can be carried out in a reasonable time. Participation in the RABBIT-SpA is open to new rheumatological institutions at any time.