The links between joint damage and disability in rheumatoid arthritis

Objective. The characteristic joint damage and disability of rheumatoid art hritis (RA) increase slowly over 10-20 yr. Although it is generally believe d that persisting inflammatory synovitis causes joint damage and subsequent disability, the strength of their relationship hits not been systematicall y evaluated. This review describes their progression and interrelationship in treated RA. Methods. MEDLINE and Current Contents databases were searched for the combi ned terms of rheumatoid arthritis AND X-rays, Health Assessment Questionnai re, slow-acting anti-rheumatic drugs and all identifiable synonyms. This se arch identified 1303 articles and from these we evaluated in detail 23 repo rts on the progression of joint damage, 12 reports on the progression of di sability and 25 reports dealing with their interrelationship. Additional in formation was obtained from four data sets comprising 725 RA patients studi ed cross-sectionally and 33-126 cases followed prospectively for 1-5 yr. X- ray damage was primarily assessed by Larsen and Sharp indices, and disabili ty by the Health Assessment Questionnaire (HAQ). Results. Joint damage and disability both increase throughout the duration of RA. Although disability (HAQ score) is correlated with disease duration (correlation coefficients between 0.27 and 0.30), the link between X-ray da mage and disability is stronger (correlation coefficients between 0.30 and 0.70). In the earliest phases of RA, X-ray damage and HAQ scores are not re lated. By 5-8 yr, there are significant correlations with correlation coeff icients between 0.30 and 0.50. In late RA (> 8 yr), most studies show highl y significant correlations between 0.30 and 0.70. Conclusions. Joint damage progresses constantly over the first 20 yr of RA. It accounts for similar to 25%, of disability in established RA. The link between damage and disability is strongest in late (> 8 yr) RA. However, av oiding or reducing joint damage in both early and established/late RA is li kely to maintain function.