[National database of German arthritis centers. Tool for health services research].

The national database of the German Collaborative Arthritis Centers is a joint venture of German rheumatology. Since 1993, all outpatients with inflammatory rheumatic diseases treated in 1 of 24 arthritis centers have been registered once a year with a clinical record form and a patient questionnaire. The aim is to continuously monitor the current state and trends in rheumatologic health care and to gain knowledge on the outcomes and burdens of diseases as well as medical, social, and economic consequences beyond the limited perspective of randomized controlled trials. Data collected for 10 years about 145,000 patients with inflammatory rheumatic diseases are available making it possible to analyze even very rare diseases with sufficient numbers of cases. Selected results concerning the health care situation in specialized and nonspecialized care, practice variations in rheumatology, and the burden of illness in various diseases are reported.