Racial and ethnic disparities in disease activity and function among persons with rheumatoid arthritis from university-affiliated clinics

OBJECTIVE

Health outcomes in rheumatoid arthritis (RA) have improved significantly over the past 2 decades. However, research suggests that disparities exist by race/ethnicity and socioeconomic status, with certain vulnerable populations remaining understudied. Our objective was to assess disparities in disease activity and function by race/ethnicity and explore the impact of language and immigrant status at clinics serving diverse populations.

METHODS

We examined a cross-sectional study of 498 adults with confirmed RA at 2 rheumatology clinics: a university hospital clinic and a public county hospital clinic. Outcomes included the Disease Activity Score in 28 joints (DAS28) and its components, and the Health Assessment Questionnaire (HAQ), a measure of function. We estimated multivariable linear regression models including interaction terms for race/ethnicity and clinic site.

RESULTS

After adjusting for age, sex, education, disease duration, rheumatoid factor status, and medication use, clinically meaningful and statistically significant differences in DAS28 and HAQ scores were seen by race/ethnicity, language, and immigrant status. Lower disease activity and better function was observed among whites compared to nonwhites at the university hospital. This same pattern was observed for disease activity by language (English compared to non-English) and immigrant status (US-born compared to immigrant) at the university clinic. No significant differences in outcomes were found at the county clinic.

CONCLUSION

The relationship between social determinants and RA disease activity varied significantly across clinic setting with pronounced variation at the university, but not at the county clinic. These disparities may be a result of events that preceded access to subspecialty care, poor adherence, or health care delivery system differences.

Socioeconomic determinants of disability and depression in patients with rheumatoid arthritis

OBJECTIVE

To examine the relationship between functional limitation, socioeconomic inequality, and depression in a diverse cohort of patients with rheumatoid arthritis (RA).

METHODS

The study design was cross-sectional and subjects were from the University of California, San Francisco RA Cohort. Patients were enrolled from 2 rheumatology clinics, an urban county public hospital and a university tertiary care medical center. Age, sex, race/ethnicity, disease activity, functional limitation, and medications were variables collected at clinical visits. The patient's clinic site was used as a proxy for his or her socioeconomic status. The outcome variable was depressive symptom severity measured by the Patient Health Questionnaire 9. Differences in characteristics between depressed and nondepressed patients were calculated using 2-sided t-tests or the Pearson's chi-square test. For the multivariate analysis, repeated measures with generalized estimating equations were used.

RESULTS

There were statistically significant differences between depressed and nondepressed patients related to race/ethnicity, public versus tertiary care hospital rheumatology clinic, disability, and medications. In the multivariate analysis, increased functional limitation and public clinic site remained significantly associated with increased depression scores. A significant interaction existed between clinic site and disability. Mean depression scores rose more precipitously as functional limitation increased at the public hospital rheumatology clinic.

CONCLUSION

There are disparities in both physical and mental health among individuals with low socioeconomic status. The psychological effects of disability vary in patients with RA such that a vulnerable population with functional limitations is at higher risk of developing depressive symptoms.

Predictors of depression in a multiethnic cohort of patients with rheumatoid arthritis

OBJECTIVE

Patients with rheumatoid arthritis (RA) who experience depression have worse health outcomes. This study identifies predictors of depression in an ethnically and racially diverse population of patients with RA.

METHODS

Patients with RA in a prospective cohort at the San Francisco General Hospital outpatient rheumatology clinic were included if they were age >or=18 years, met the American College of Rheumatology classification criteria for RA, had a Health Assessment Questionnaire (HAQ) score collected, and had the RA-specific Disease Activity Score performed by a rheumatologist. The outcome variable was a depression score measured by the Patient Health Questionnaire 9 (PHQ-9), a self-report questionnaire validated to correlate with a diagnosis of major depression.

RESULTS

Three hundred forty-nine clinical visits for 172 patients were included in the analysis. Forty percent of patients scored >or=10 on the PHQ-9 during at least one clinic visit, which corresponds to a symptom severity of at least moderate depression. The mean PHQ-9 score was 7, corresponding to a symptom severity of mild depression. In the multivariate analysis, higher HAQ scores were associated with depression, and Asians had lower depression scores compared with Hispanic, white, and African American subjects.

CONCLUSION

Identifying associated predictors of depression in a diverse population of patients with RA can help guide treatment, which should include preventing disability and decreased function as well as targeting depressive symptoms more specifically in patients with RA.