Global Incidence and Burden of RA Predicted to Increase Over Time

The global prevalence and burden of rheumatoid arthritis (RA) are expected to increase over the next 20 years, necessitating interventions for prevention and early treatment, according to study results published in Clinical Rheumatology.

Rheumatoid Arthritis, a chronic autoimmune joint disease, poses a significant public health problem with a high burden of functional disability. While global incidence and prevalence of RA have increased, region-specific trends are underreported. Researchers aimed to assess secular trends in RA incidence and burden on regional and national levels.

The researchers obtained data on RA incidence, prevalence, and years lived with disability (YLD) from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019. GBD 2019 analyzed the burden of disease among 204 countries, from 1990 to 2019. Disease prevalence was stratified by severity using International Classification of RA disease codes. Secular trends were calculated using age-standardized rates and estimate annual percentage changes (EAPC).

The researchers estimated a 1.06-fold increase in RA prevalence from 1990 to 2019, corresponding with 18.5 million prevalent diagnosed cases of RA. According to GBD 2019 estimates, the age-standardized prevalence rates (ASPR) and age-standardized incidence rates (ASIR) for RA were 224.25 per 100,000 persons and 12.21 per 100,000 persons, respectively. Incident and prevalent EAPCs were found to be 0.37 (95% CI, – 0.32 to 0.42) and 0.30 (95% CI, 0.25-0.34), respectively.

Global ASIRs were higher among women and increased with age, with highest rates among those aged 70 to 74 years. Similarly, ASPRs were also higher among women, peaking among those aged 60 to 64 years.

Surprisingly, lower social demographic index (SDI), a composite measure of regional income, education, and fertility, was correlated with lower YLD (eg, higher income regions displayed a greater than expected burden of disease) (R = 0.28; P <.001).

Researchers project the ASIRs from 2019 to 2040 will be 10.48 per 100,000 persons and 4.63 per 100,000 persons for women and men, respectively.

This study was limited by flaws in GBD 2019 research methods. Additionally, differences in regional diagnostic criteria of RA may limit comparisons.

The researchers concluded, “Our findings emphasize the need for public policy interventions through disease prevention projects. Public awareness of modifiable risk factors, prevention, and early treatment is pivotal to avoiding the onset and alleviating the enormous burden of RA.”