OBJECTIVES: To describe drug use, drug switch and cost evaluation in patients with rheumatoid arthritis (RA). METHODS: Data derived from ARNO Observatory, an Italian population-based patient-centric system through record linkage of 11 million inhabitants. In a sub-cohort of 5,821,337 people, we identified 15,082 subjects with rheumatoid arthritis in 2011.  Data were retrived for all these patients back to 2010 in order to esteem disease incidence. A cohort matched by sex, age and local health unit was computed to estimate differences in health costs. RESULTS: Prevalence of RA was 0.26% with an average age of 62 years and a percentage of women of 77%. Incidence is about 0.03% per year. The cost per-person is €2,823 per year, 128% more in comparison with pair-matched group. This cost is for €1,230 due to drugs (€564 specific drugs, €666 others), €1,024 due to hospitalization and €569 due to lab tests and diagnostic examinations. Most common drugs are methylprednisolone + prednisone (63% treated), methotrexate (47.2%) and hydroxychloroquine (31.6%). Biological drugs are used by 3% of patients, but this percentage is increasing by years. Patients treated with biological drugs cost three times higher than others. Patients usually start first treatment with methylprednisolone + prednisone (46.6%), 25.2% start with methylprednisolone + prednisone and other specific drugs and 12.1% with methotrexate. One year after the first treatment only 40.1% of patients continue receiving the same treatment, 41.4% add a specific drug, 11.7% leave therapy and 6.8% switch to another specific drug. CONCLUSIONS: This administrative database is an important source of information that is able to show both economical indicators and the good practice of treatment. In this study, they point out an elevated cost per-person in drugs assumption and show very current tendency to switch therapy in the first year.