Cost of illness studies in rheumatic diseases.

Knowledge about the economic burden of rheumatic diseases has progressed during recent years. In addition to the increasing number of studies published, the Economics Working Group of the Outcome Measures in Rheumatoid Arthritis Clinical Trial (OMERACT) Conference has produced substantial work to improve methodological standards for the economic evaluation of rheumatic diseases. Some of their preliminary results are presented in this review. Recent data have confirmed two main conclusions of previous studies: the total economic burden of rheumatic diseases is often more substantial than other chronic conditions, including cardiovascular diseases and cancer; and the impact of the disability caused by musculoskeletal diseases is significant on both direct (long-term care in osteoporosis for example) and indirect costs (productivity loss in chronic patients). Besides that, cost-effectiveness studies have provided valid information to improve disease management, especially for patients with rheumatoid arthritis or chronic low back pain.