Objective. The development and validation of Modified Disease Activity Scores (DAS) that include different 28-joint counts.Methods. These scores were developed by canonical discriminant analyses and validated for criterion, correlational, and construct validity. The influence of disease duration on the composition of the DAS was also investigated.

Objective. To validate the European League Against Rheumatism (EULAR), the American College of Rheumatology (ACR), and the World Health Organization (WH0)hnternational League Against Rheumatism (ILAR) response criteria for rheumatoid arthritis (RA).Methods. EULAR response criteria were developed combining change from baseline and level of disease activity attained during followup. In a trial comparing hydroxychloroquine and sulfasalazine, we studied construct (radiographic progression), criterion (functional capacity), and discriminant validity.Results. EULAR response criteria had good construct, criterion, and discriminant validity. ACR and WHO/ILAR criteria showed only good criterion validity.Conclusion. EULAR response criteria showed better construct and discriminant validity than did the ACR and the WHOIILAR response criteria for RA.

In a prospective Ibllow-up study of patients with early-onset rheumatoid arthritis, the prevalence of remission according to the 1981 American Rheumatism Association (ARA) preliminary criteria was evaluated. A total of 227 patients with a median follow-up of 3.9 yr and a total of 2832 follow-up visits were studied. The ARA remission criteria were fulfilled in 9.5% of these visits. The percentage of patients with at least one visit fulfilling the ARA criteria was for years 2 6 ~ 25%. Each year, 15% of the patients were in remission for at least two consecutive visits. A comparison was made between the ARA remission criteria and the Disease Activity Score (DAS). DAS <1.6 corresponded with being in remission according to the ARA criteria. The DAS is being proposed as a tool to define remission because absence of disease activity should be measured using the same method as for higher levels of disease activity, preferably on a continuous scale.

Socio-economic change already presents in the first years of RA and appears to be influenced by age, gender, marital status and work disability. Furthermore, physical limitation appeared to be predictive for work-related income reduction, reduced transport mobility and development of social dependency.

This prospective longitudinal study evaluates the validity and reliability of joint indices (JIs) used to measure disease activity in patients with RA. From seven traditional JIs (Ritchie Articular Index (RAI), Modified RAI, Thompson score, 28 JI, 36 JI, total tender and total swollen joints) 37 'new' JIs were computed by considering three different characteristics of joint inflammation, tenderness, swelling and the combination of tenderness and swelling, and by grading for tenderness and/or weighting for surface area of the joints. Several aspects of validity were investigated, the construct (correlation with radiographic damage), correlational (correlation with ESR, general health) and criterion validity (correlation with a Health Assessment Questionnaire, discrimination between high and low disease activity). It was found that the validity and reliability of traditional JIs do not differ substantially. Graded JIs are almost always more valid than ungraded JIs. Weighted JIs are almost always less valid and reliable than unweighted JIs. Therefore no JI proved to be superior for measuring the disease activity under consideration. Taking simplicity into account the 28 JI, not graded and not weighted, was preferable.