A pilot study to determine whether disability and disease activity are different in African-American and Caucasian patients with rheumatoid arthritis in St. Louis, Missouri, USA.

OBJECTIVE: To compare the levels of disability and disease activity in African-Americans and Caucasians with rheumatoid arthritis (RA) in an academic medical center practice, and to determine whether the differences are independently associated with ethnicity.
METHODS: Data on socioeconomic, disease related, psychological, and behavioral variables were obtained from 100 outpatients (67 Caucasians, 33 African-Americans) with RA. Functional status was assessed with the Health Assessment Questionnaire (HAQ) and Disease Activity Score (DAS-28). Chi-square and Student t tests were used to test for differences between groups. Multiple regression analysis was used to determine whether ethnicity was associated with these differences independent of other factors known to influence disease outcome.
RESULTS: African-Americans and Caucasians did not differ with respect to age, sex, disease duration, rheumatoid factor positivity, and medication compliance. African-Americans had higher scores than Caucasians for HAQ (1.5 +/- 0.8 vs 0.9 +/- 0.7; p < 0.001) and DAS-28 (5.5 +/- 1.3 vs 4.3 +/- 1.4; p < 0.001). Regression models showed that ethnicity was not independently associated with the higher HAQ and DAS-28 scores when controlled for demographic, socioeconomic, psychological, and behavioral factors. Arthritis self-efficacy approaches significance in the regression model.
CONCLUSION: HAQ disability and RA disease activity were higher in African-Americans than Caucasians in this sample from an academic medical center practice. However, ethnicity was not independently associated with these outcomes when socioeconomic and psychological factors were taken into account. Improvement in self-efficacy has the potential to improve outcome in African-Americans with RA.