We administered the Stanford Health Assessment Questionnaire functional disability questionnaire to a cohort of 400 patients with rheumatoid arthritis (RA) every 6 months during a mean followup of 3.1 years. Simple classification into 3 groups based on Functional Disability Index (FDI) scores (0-1, 1.1-2, 2.1-3) identified patients with increasingly more severe scores for clinical, psychological, and demographic variables; and FDI scores at entry predicted increased inpatient and outpatient utilization of services, and mortality. The FDI provided important and clinically useful current and predictive information regarding RA status, utilization of services, and mortality that was not available through conventional testing. Our data suggest that such information can be easily and inexpensively obtained.