THE LONG-TERM OUTCOMES OF RHEUMATOID-ARTHRITIS - WORK DISABILITY - A PROSPECTIVE 18 YEAR STUDY OF 823 PATIENTS

Objective. Work disability is a common outcome of rheumatoid arthritis (RA). Yet there have been no longitudinal, longterm, prospective stud ies of work disability in this illness. This 18 year longitudinal stud y investigates the rate of work disability, its concomitants, and its predictors, using a large series of clinical, laboratory, and self-rep ort measures. Methods. In 1974, a computerized database was developed for the contemporaneous entry of all patient visits. Data included cli nical, laboratory, and self-report information. Patients were also ass essed by mailed questionnaires at 6 month intervals. In 1994, patients with RA were interviewed in detail about lifetime work status and wor k disability. Results. Work disability was estimated to occur in 25% a t 6.4 years and 50% at 20.9 years after disease onset, and most disabi lity occurred late in the course of disease. Work disability was predi cted by almost every demographic and clinical variable. Education leve l, body mass index (BMI), erythrocyte sedimentation rate, rheumatoid f actor, pain, Health Assessment Questionnaire (HAQ) disability, and phy sical demands of the job were independently associated with disability . Over the course of their illness, the work disabled had a 35% reduct ion in family income, and had more abnormal scores for joint counts, g rip strength, sedimentation rate, pain, global severity, HAQ disabilit y, and anxiety and depression. Except for BMI, the results were essent ially similar in a subset of 156 patients seen first with a disease du ration of less than one year. Conclusion. Work disability can be predi cted by patient and work characteristics present at the first clinic v isit, but it is persistent abnormalities of sedimentation rate, HAQ di sability, and pain, which may be detected in longitudinal followup, th at best predict work disability after work and demographic characteris tics are accounted for.