Rheumatoid Arthritis Cases Rise by 13 Percent Globally, Affecting Younger Populations: Study

Rheumatoid arthritis (RA) affected nearly 18 million people worldwide in 2021, marking a 13.2% increase in incidence since 1990, according to a new study published in the Annals of the Rheumatic Diseases. The study, part of the Global Burden of Disease (GBD) project led by the Institute for Health Metrics and Evaluation at the University of Washington, also found that Rheumatoid arthritis is becoming more prevalent among younger populations and across a broader geographic range.

Rheumatoid arthritis is a chronic autoimmune disorder in which the body’s immune system attacks healthy tissues, particularly the joints, leading to pain, stiffness, and inflammation. The latest study analyzed data from more than 200 countries and territories between 1990 and 2021, offering one of the most detailed insights into Rheumatoid arthritis trends to date.

"In 2021, Rheumatoid arthritis affected 17.9 million people globally, with a 13.2 per cent increase in incidence rate from 1990–2021, trending younger and broader," the authors wrote. They attributed this rise in part to population growth, which influenced disease burden in countries like India, Pakistan, and Spain. In contrast, ageing was the dominant factor in countries such as Thailand, China, and Poland.

"While previous Global Burden of Disease (GBD) studies have provided important insights, they have largely focused on high-level descriptions and visualisations at global and national scales, failing to capture local disparities or the dynamic interactions between socioeconomic development and disease trends," said Queran Lin, the study’s principal investigator from Imperial College London.

Interestingly, the burden was highest in regions with a high sociodemographic index (SDI), though these areas also began to see improvements. Japan, for instance, reduced Rheumatoid arthritis burden by over 22%, thanks to early diagnosis, access to biologic treatments, and an anti-inflammatory diet. Meanwhile, low- and middle-SDI regions are projected to see increased burden by 2040 due to ageing and population growth. The study emphasized that controlling smoking—particularly in high-prevalence areas like China—could reduce Rheumatoid arthritis -related deaths by 16.8% and decrease overall disease burden by over 20%.

Reference: Spatiotemporal distributions and regional disparities of rheumatoid arthritis in 953 global to local locations, 1980-2040, with deep learning-empowered forecasts and evaluation of interventional policies’ benefits, Jin, Wenyi et al., Annals of the Rheumatic Diseases, Volume 0, Issue 0