Links between radiological change, disability, and pathology in rheumatoid arthritis.

The relationship between the development of radiographic joint destruction in rheumatoid arthritis and its longterm consequences for the patient is not well understood. Two objectives for further research have been identified: elucidating this relationship and relating pathological processes to the features visible on radiographs. Extrapolation from a proposed model suggests that if radiographic progression is suppressed early in the disease, it might take many years before the benefit can be clearly appreciated against a background of variation within individual patients. Two approaches have recently been brought to bear on this issue, including a detailed modeling of medium term observations from a single dataset and a review of a large number of published studies. There are a number of reservations about the notion of a minimum clinically important change, but one possibility for defining such a change for radiographs is in relation to longterm functional outcome.