Discriminative power of Larsen's grading system for assessing the course of rheumatoid arthritis

In the classification of 18628 joints in 186 patients with rheumatoid arthritis during a follow-up of 3 to 12 years, the discriminative power of Larsen's scoring system was assessed. Obvious radiologic progression did not give rise to a change of grading in 9.5 per cent of the examinations. For investigations with a relatively short observation period, more detailed scoring systems should therefore be used.