Assessing outcome in acute illness and chronic conditions with well defined end-points, is simple. However, assessing outcome in slowly progressive chronic diseases with natural fluctuations in clinical course is a major challenge. Most chronic musculoskeletal diseases fall in the latter category with rheumatoid arthritis (RA) as its prototype. To make matters worse, there are several aspects of musculoskeletal disease that need to be assessed over time. Degree of synovial inflammation, extent of structural damage, the degree of functional derangement, all need to be assessed separately at intervals. Any intervention must favourably affect each of these parameters to be meaningful to the patient. Having to deal with this problem in routine clinical practise as well as clinical research, rheumatologists have been pioneers in the development and use of clinical measures for outcome assessment in chronic fluctuating illnesses.
This review summarizes the advances in the field of outcome assessment for RA with emphasis on decreased synovitis. For clinical research the use of Paulus statistics and ACR improvement criteria using a core-set of parameters is recommended. For day-to-day assessment in the clinic DAS28 pooled-index is recommended. Use of DAS28 is easy and quick, yet it gives internationally acceptable objective assessment of disease activity that compares well with ACR criteria. Availability of DAS28 Calculator v1.1-beta on-line at web site www.das-score.nl or http://www.das-score.nl/www.das-score.nl/DAS28-ne.xls. that performs all the calculations automatically makes it even easier to use in a busy clinic.