Clinical judgment analysis has been used to investigate differences in assessing disease activity in rheumatoid arthritis. Rheumatologists as a group do not adopt a single underlying policy for the assessment of changes in disease activity; each has his or her own approach to such judgements. Some rheumatologists are inconsistent in applying their judgment policies, leading to disagreements even when underlying policies are similar. Having identified these problems of assessment, clinical judgement analysis may be employed to reduce clinical disagreement and to improve coordination and consistency between rheumatologists in different centres during clinical investigations.