Mental and physical illnesses, such as rheumatoid arthritis, are often driven by social, environmental, and economic factors and may affect disease outcomes.
A systematic literature review (SLR) indicated that low socioeconomic status (SES) was associated with worse outcomes in patients with rheumatoid arthritis (RA), according to a study published in Rheumatic and Musculoskeletal Diseases.1
“Physical and mental illnesses are driven by social, environmental, and economic determinants,” investigators stated. “SES is also closely associated with lifestyle and other factors which affect disease outcomes in RA, such as smoking, body mass index (BMI), diet and comorbidities, for example, cardiovascular disease and diabetes.”
The SLR identified English-language articles that analyzed the association between SES and disease activity in adult patients with RA from 1946 to March 2021 by using the question: Is there an association between social deprivation and disease activity in people with RA? Articles were examined and screened by 2 investigators, with inclusion disagreements resolved by a third reviewer. Information, such as education, employment, ethnicity, the definition and measure of SES, disease activity, comorbidities, and the presence or absence of the association between SES and disease activity were collected. The main outcome focused on disease activity, defined by the disease activity score (DAS), which included DAS28 measurements, European Alliance of Associations for Rheumatology (EULAR) responses, and American College of Rheumatology (ACR) responses, inflammation, refractory disease, and difficult-to-treat arthritis.
Of the 1750 articles originally identified, 30 articles (20 cohort, 9 cross-sectional, and 1 case-control) were ultimately included in the assessment. The definition of SES varied, with 10 (33%) articles utilizing a formal scale and most using educational achievement, either by itself or in conjunction with other factors, such as occupation, ethnicity, income, area of residence, and employment status. Most of the studies controlled for lifestyle factors, such as BMI, comorbidities, and smoking.
Most (n = 25, 83%) studies found a clear association between SES and worse outcomes and/or increased disease activity. One study that used relative risk ratios (RRRs) found that patients with higher levels of education had a lower relative risk of worse disease outcomes and another study calculated the percentage of patients with treatment-resistant disease who could not afford biologics, which was their definition of low SES.
Three (10%) studies found no association and 2 (7%) were unclear.
Strengths of the study included the targeted search strategy and objective clinical measures of disease activity for comparison. However, the search strategy may have excluded studies that reviewed additional social factors. Qualitative studies may have also been excluded due to the focus on objective measures of disease activity. The strategy did, however, allow for comparison between studies and highlight the need for mixed-methods studies. There is a possibility of reporting bias in the studies that were ultimately included, as investigators and publishers may be biased towards positive associations. Lastly, it was not possible to conduct a meta-analysis due to the variety of reporting of outcomes and between outcomes themselves.
“We have highlighted the complex multifaceted relationships giving rise to the association [between low SES and worse disease outcomes in patients with RA],” investigators concluded. “There is a need for increased use of mixed-methods methodologies and consideration of tools such as PROGRESS and syndemic frameworks to understand bio–bio and bio–social interactions, to study drivers of disease and poor outcomes more holistically. These frameworks take a concentrated approach on how best to measure and finally tackle social deprivation, not just in RA, but across long-term conditions.”
Dey M, Busby A, Elwell H, et al. Association between social deprivation and disease activity in rheumatoid arthritis: a systematic literature review. RMD Open. 2022;8(1):e002058. doi:10.1136/rmdopen-2021-002058