The study protocol of the long-term observational study RABBIT was approved by the ethics committee of the Charité, Universitätsmedizin Berlin in 2001; amendments required for enrolment of further licensed biologic DMARDs were approved respectively.
Prior to their enrolment in RABBIT, patients receive all required information concerning their participation in the long-term observation both verbally and in written form from their rheumatologist. If they agree, they give their informed consent. Afterwards, they are eligible for enrolment in RABBIT. Patients can withdraw from the study at any time without giving reasons. Since impairment of the health status is one of the main reasons for dropping out, and all information on patients’ health status is very important for the study, we kindly ask all patients to provide their reason for withdrawal and contact them by letter or sometimes also by calling.
Participating rheumatologic departments mail the original informed consent back to the German Rheumatism Research Center (DRFZ) in Berlin. Soon after completion, copies of the questionnaires are sent back by fax; original questionnaires are preserved in the patients’ records in the respective departments. According to the requirements of medical data protection, all personal data of the patients and data of the questionnaires are kept strictly separated in the DRFZ; personal data are stored in a locked steel cabinet.
At the DRFZ, each participating department and each patient are provided with a particular encryption number. All questionnaires are exclusively identified with this encryption number. During assessment, management, and analysis of research data as well as in the publication of results the identification of a patient is not possible.