Arthritis and other rheumatic conditions are among the most prevalent diseases in the United States, particularly for women and some racial/ethnic groups. In 1992, arthritis was the leading cause of disability and was associated with total direct and indirect costs of $64.8 billion; projections indicate that by 2020, arthritis will affect 59.4 million (18.2%) persons in the United States. Previous reports have documented marked differences in the prevalence rates of arthritis by age, sex, race, ethnicity, education, and body mass index (BMI). To examine the relative importance of these factors, CDC used data from the 1989-1991 National Health Interview Survey (NHIS) and a multivariate model to estimate the independent effect of each factor on self-reported arthritis. This report summarizes the results of that analysis, which indicate that a higher risk for arthritis is associated with older age, overweight, or obesity and that a lower risk is associated with being Asian/Pacific Islander or Hispanic or with having a higher education level.