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. 2021 Aug 2;4(8):e2119400.
doi: 10.1001/jamanetworkopen.2021.19400.

Socioeconomic Disparities in Functional Status in a National Sample of Patients With Rheumatoid Arthritis

Zara Izadi  1   2 , Jing Li  2 , Michael Evans  2 , Nevin Hammam  2 , Patricia Katz  2 , Alexis Ogdie  3 , Lisa G Suter  4   5 , Jinoos Yazdany  2 , Gabriela Schmajuk  2   6
Affiliations

Socioeconomic Disparities in Functional Status in a National Sample of Patients With Rheumatoid Arthritis

Zara Izadi et al. JAMA Netw Open. .

Abstract

Importance: Little is known about the association of poverty with functional status (FS) in patients with rheumatoid arthritis (RA) who use rheumatology care.

Objectives: To examine the association between socioeconomic status (SES) and FS among patients with RA and to evaluate the association between SES and functional declines over time in patients who received at least some rheumatology care.

Design, setting, and participants: This cohort study used data from the American College of Rheumatology's Rheumatology Informatics System for Effectiveness (RISE) registry between January 1, 2016, and December 31, 2018. Analyses included all adult patients with a confirmed RA diagnosis (ie, had ≥2 encounters associated with RA International Classification of Diseases codes ≥30 days apart) and at least 1 FS score documented between 2016 and 2018 seen at participating rheumatology practices. Data analysis was conducted from April to December 2020.

Exposures: The Area Deprivation Index (ADI), a zip code-based indicator of neighborhood poverty, was used as a proxy for SES. ADI scores were categorized into quintiles.

Main outcomes and measures: FS measures included Multidimensional Health Assessment Questionnaire (MDHAQ), Health Assessment Questionnaire Disability index, and Health Assessment Questionnaire-II. Cross-sectionally, mean FS scores were compared across ADI quintiles. Longitudinally, among patients with at least 2 FS scores, multilevel multivariate regression computed the probability of functional decline, defined as a change greater than the minimum clinically important difference, across ADI quintiles. In a subgroup analysis, whether disease activity mediated the association between SES and functional decline was examined.

Results: Of the 83 965 patients included in the study, 66 649 (77%) were women, and 60 037 (72%) were non-Hispanic White. Mean (SD) age was 63.4 (13.7) years. MDHAQ was the most reported FS measure (56 928 patients [67.8%]). For all measures, mean (SD) FS score was worse at lower SES levels (eg, for MDHAQ quintile 1: 1.79 [1.87]; quintile 5: 2.43 [2.17]). In longitudinal analyses, the probability of functional decline was 14.1% (95% CI, 12.5%-15.7%) in the highest SES quintile and 18.9% (95% CI, 17.1%-20.7%) in the lowest SES quintile. The association between SES and functional decline was partially mediated (7%; 95% CI, 4%-22%) by disease activity.

Conclusions and relevance: In this cohort study of patients with RA, worse FS and faster declines in functioning over time were observed in patients with lower SES. These findings provide a framework for monitoring disparities in RA and for generating evidence to spur action toward achieving health equity.

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Conflict of interest statement

Conflict of Interest Disclosures: Drs Yazdany and Schmajuk reported being supported by the Russell/Engleman Medical Research Center for Arthritis. Dr Katz reported receiving grants from the National Institutes of Health, the Department of Defense, and Genentech and receiving personal fees from FORWARD The National Databank for Rheumatic Diseases outside the submitted work. Dr Ogdie reported receiving grants from Abbvie, Pfizer, and Novartis to Penn; grants from Amgen to FORWARD; personal fees from Abbvie, Amgen, Bristol Myers Squibb, CorEvitas, Celgene, Eli Lilly and Co, Gilead, Janssen Pharmaceuticals, Novartis, Pfizer, and Berkeley Consulting; and that husband received royalties from Novartis outside the submitted work. Dr Suter reported receiving support for directing a federal contract from the Centers for Medicare & Medicaid Services, unrelated to this work, during the conduct of the study; receiving grants from Brigham and Women’s Hospital; and consulting fees from the National Institutes of Health outside the submitted work. Dr Yazdany reported receiving grants from Gilead and Bristol Myers Squibb and personal fees from AstraZeneca, Eli Lilly and Co, Aurinia, and Pfizer outside the submitted work. Dr Schmajuk reported receiving a contract from the American College of Rheumatology during the conduct of the study. No other disclosures were reported.

Figures

Figure 1.
Figure 1.. Mean Functional Status Measure Scores Across Quintiles of Area Deprivation Index in the Cross-Sectional Analysis
Error bars represent 95% confidence interval for the means. Statistical significance of a linear trend across the quintiles of socioeconomic status (SES) was tested separately for each functional status measure using a Wald test on marginal linear predictions; all tests were statistically significant at the P < .05 level. HAQ indicates Health Assessment Questionnaire Disability index; HAQ-II, Health Assessment Questionnaire–II; MDHAQ, Multidimensional Health Assessment Questionnaire.
Figure 2.
Figure 2.. Computed Probabilities of Functional Decline Across Quintiles of Area Deprivation Index in the Longitudinal Analysis
The multivariate model was adjusted for age, sex, race/ethnicity, baseline functional status, medication prescribed, number of visits, duration between the 2 functional status scores, and within-practice correlations. Error bars represent 95% CIs for computed probabilities. Statistical significance of a linear trend across the quintiles of socioeconomic status (SES) was tested using a Wald test on marginal linear predictions; the test was statistically significant at the P < .05 level.
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References

    1. Barton JL, Trupin L, Schillinger D, et al. . Racial and ethnic disparities in disease activity and function among persons with rheumatoid arthritis from university-affiliated clinics. Arthritis Care Res (Hoboken). 2011;63(9):1238-1246. doi:10.1002/acr.20525 - DOI - PMC - PubMed
    1. Margaretten M, Barton J, Julian L, et al. . Socioeconomic determinants of disability and depression in patients with rheumatoid arthritis. Arthritis Care Res (Hoboken). 2011;63(2):240-246. doi:10.1002/acr.20345 - DOI - PMC - PubMed
    1. Greenberg JD, Spruill TM, Shan Y, et al. . Racial and ethnic disparities in disease activity in patients with rheumatoid arthritis. Am J Med. 2013;126(12):1089-1098. doi:10.1016/j.amjmed.2013.09.002 - DOI - PMC - PubMed
    1. Katz PP, Barton J, Trupin L, et al. . Poverty, depression, or lost in translation? ethnic and language variation in patient-reported outcomes in rheumatoid arthritis. Arthritis Care Res (Hoboken). 2016;68(5):621-628. doi:10.1002/acr.22748 - DOI - PMC - PubMed
    1. van Der Heijde D. Impact of rheumatoid arthritis on physical function during the first five years: no longer a question mark? Rheumatology (Oxford). 2000;39(6):579-580. doi:10.1093/rheumatology/39.6.579 - DOI - PubMed

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