Gaps in Arthritis Subtype Awareness Highlight Health Literacy Disparities Among US Adults

More than 1 in 5 US adults with arthritis do not know their specific subtype, with a lack of awareness disproportionately affecting certain racial and ethnic groups, as well as individuals with lower income, less education, and no health insurance, according to a study published in the CDC’s Preventing Chronic Disease.1

Arthritis is one of the most common chronic diseases in the US, affecting an estimated 53.2 million adults.2 This number is projected to increase to 78.4 million by 2040.3 The term “arthritis” encompasses over 100 conditions, each with different symptoms, treatments, etiologies, and pathogeneses.4

Consequently, the researchers emphasized the importance of individuals with arthritis knowing their specific subtype to support effective disease management. They added that having up-to-date prevalence estimates for various arthritis subtypes can help inform public health policies, support prevention programs, and allocate resources effectively.

Despite its importance, limited research has examined the prevalence and distribution of arthritis subtypes among US adults. To fill this gap, the researchers analyzed data from the National Health and Nutrition Examination Survey collected between 2017 and March 2020.

The study found that the overall crude prevalence of any diagnosed arthritis among US adults aged 20 or older was 27.9%, affecting about 67.1 million individuals (95% CI, 23.5%-30.6%). The overall age-standardized prevalence was 24.9% (95% CI, 23.2%-26.7%).

These significant gaps in arthritis subtype awareness among US adults underscore the need for improved health literacy and more targeted public health efforts. | Image Credit: Evrymmnt - stock.adobe.com

Osteoarthritis was the most common subtype, affecting an estimated 33.2 million US adults (crude prevalence, 49.6%; age-standardized prevalence, 44.5%). This was followed by rheumatoid arthritis, which impacted 10.6 million people (crude, 15.8%; age-standardized, 18.9%), and psoriatic arthritis, which affected 1.0 million people (crude, 1.4%; age-standardized, 1.7%).

Additionally, more than 1 in 10 individuals with arthritis reported having an unlisted type of arthritis (n = 7.7 million; crude, 11.5%; age-standardized, 15.6%), and about 1 in 5 affected adults did not know their specific arthritis type (n = 14.4 million; crude, 21.6%; age-standardized, 22.3%).

The age-standardized prevalence of not knowing one’s arthritis type was higher among certain racial and ethnic groups. Among adults who self-identified as Mexican American, 31.9% were unaware of their arthritis type, compared with 20.2% of non-Hispanic White adults (P = .03). Similarly, the prevalence was 26.7% among non-Hispanic Black adults and 29.5% among other Hispanic adults.

The data also showed a clear association between educational attainment and arthritis type awareness, with the prevalence of not knowing increasing as educational attainment decreased (P = .006). Adults with a college degree (14.8%) had a lower prevalence of not knowing their arthritis type compared with those with some college education (23.4%; P = .02), a high school education (24.1%; P = .03), or less than a high school education (31.8%; P = .005).

Income level also played a role. Adults with a family income at or below 125% of the federal poverty level (FPL) had a higher prevalence of not knowing their arthritis type (26.7%) than those with a family income above 400% of the FPL (16.6%; P = .004). Lastly, a lack of health insurance was another significant factor, with 36.1% of uninsured adults unaware of their arthritis type compared with 20.7% of insured adults (P = .03).

The researchers concluded by acknowledging their limitations, including the fact that arthritis subtypes were self-reported and not validated by a health care professional. As a result, recall bias may have led to misclassification of arthritis types, affecting the accuracy of prevalence estimates.

Nonetheless, they expressed confidence in their findings, which highlight a broader issue of health literacy in the US. The researchers stressed that understanding one’s arthritis type is essential for effective treatment, self-management, and improved health outcomes.

“Knowing arthritis type is crucial for successfully managing the disease and preventing further damage,” the authors wrote. “Using strategies to improve organizational and personal health literacy could contribute to more informed patients, thereby reducing the prevalence of not knowing arthritis type and improving health outcomes.”

References

1. Foster AL, Boring MA, Lites TD, Croft JE, Odom EL, Fallon EA. Distribution of arthritis subtypes among adults with arthritis in the United States, 2017-March 2020. Prev Chronic Dis. 2025;22:E28. doi:10.5888/pcd22.240393
2. Fallon EA, Boring MA, Foster AL, et al. Prevalence of diagnosed arthritis - United States, 2019-2021. MMWR Morb Mortal Wkly Rep. 2023;72(41):1101-1107. doi:10.15585/mmwr.mm7241a1
3. Hootman JM, Helmick CG, Barbour KE, Theis KA, Boring MA. Updated projected prevalence of self-reported doctor-diagnosed arthritis and arthritis-attributable activity limitation among US adults, 2015-2040. Arthritis Rheumatol. 2016;68(7):1582-1587. doi:10.1002/art.39692