Global disease burden of immune‐mediated inflammatory diseases (IMIDs), 1990–2021

Each year, millions worldwide grapple with immune-mediated inflammatory diseases (IMIDs)—a group of chronic conditions including asthma, rheumatoid arthritis, and type 1 diabetes—that cause significant disability and mortality.  In a landmark study published in Med Research, an international research team unveils the most comprehensive analysis to date of IMIDs’ global burden from 1990–2021, with projections to 2046, using data from the Global Burden of Disease (GBD) 2021 study.

The study reveals a paradox: while age-standardized mortality and disability rates (ASMR, ASDR) fell globally (driven by asthma improvements), incidence rates (ASIR) rose in high-income regions due to better diagnostics and lifestyle factors like obesity.  Strikingly, Haiti recorded the highest asthma incidence (1,617 per 100,000), while Papua New Guinea faced the worst mortality.  A surprising 2005–2010 spike in diagnoses across all regions was linked to updated clinical guidelines uncovering hidden cases.

"Women and children bear a disproportionate burden," explains one of the study's authors, Xueping Zhu." For instance, female ASIR was 4% higher than males, partly due to hormonal impacts on immunity and delayed diagnoses.  Meanwhile, asthma and type 1 diabetes peaked in children under 10, while rheumatoid arthritis surged in seniors."

The study's multidisciplinary team of scientists uncovered a critical divide:  higher sociodemographic index (SDI) regions correlated with lower mortality (better healthcare) but higher incidence (enhanced detection and environmental risks).  Asthma skewed toward low-SDI populations (e.g., ASDR concentrated in disadvantaged groups, CI: −0.27), while psoriasis and rheumatoid arthritis disproportionately affected wealthier regions.

To predict future trends, the study's team employed advanced ARIMA modeling—unusual for large-scale epidemiological forecasts—revealing optimistic projections: by 2046, global ASIR, ASDR, and ASMR could drop by 36.5%, 41.2%, and 74.9%, respectively.  Yet, disparities persist: the UK and Haiti will still face high disability burdens, while asthma mortality remains concentrated in Pacific nations like Papua New Guinea.

"This work reshapes how we view IMIDs," emphasized Xin Guan, the investigator who led the study.  "The decline in mortality proves targeted therapies and early screening work.  But the rising incidence in wealthy regions signals new challenges—like obesity’s role—demanding tailored prevention."  The study urges policymakers to address inequality: "Investing in low-SDI regions and gender-specific care is vital.  Our projections show progress is possible, but only if we act on these insights."