[The National Database of the German Arthritis Centres--a 12 year balance].

The National Database of the German Collaborative Arthritis Centres is the most important source for the evaluation of current health care for German rheumatology patients. Since 1993, all outpatients with inflammatory rheumatic diseases treated in one of 24 arthritis centres have been recorded once a year using a clinical record form and a patient questionnaire. The aim is to gain knowledge on the outcomes and the medical, social and economic consequences of inflammatory rheumatic diseases in the real world, and to monitor continuously the current state and trends in health care. Data from more than 200,000 patients with inflammatory rheumatic diseases from 11 years (1993-2003) are available, making it possible to analyse even very rare diseases with a sufficient numbers of cases. Selected results on the health care situation, practice variation in rheumatology and the burden of illness in various diseases are reported.