Around 5% of US Population Diagnosed With Autoimmune Disease

TOPLINE:

In 2022, autoimmune diseases affected over 15 million individuals in the United States, with women nearly twice as likely to be affected as men, and more than one third of affected individuals having more than one autoimmune condition.

METHODOLOGY:

• Researchers used electronic health record (EHR) data from six healthcare systems in the United States between 2011 and 2022 to estimate the prevalence of autoimmune diseases according to sex and age.
• They selected 105 autoimmune diseases from the textbook ‘The Autoimmune Diseases’ and estimated their prevalence in more than 10 million individuals from these healthcare systems; these statistics were subsequently extrapolated to an estimated U.S. population of 333.3 million.
• An individual was considered to have a diagnosis of an autoimmune disease if they had at least two diagnosis codes for the condition, with the codes being at least 30 days apart.
• A software program was developed to compute the prevalence of autoimmune diseases alone and in aggregate, enabling other researchers to replicate or modify the analysis over time.

TAKEAWAY:

• More than 15 million people, accounting for 4.6% of the US population, were diagnosed with at least one autoimmune disease from January 2011 to June 2022; 34% were diagnosed with more than one autoimmune disease.
• Sex-stratified analysis revealed that 63% of patients diagnosed with autoimmune disease were women, and only 37% were men, establishing a female-to-male ratio of 1.7:1; age-stratified analysis revealed increasing prevalence of autoimmune conditions with age, peaking in individuals aged ≥ 65 years old.
• Among individuals with autoimmune diseases, 65% of patients had one condition, whereas 24% had two, 8% had three, and 2% had four or more autoimmune diseases (does not add to 100% due to rounding).
• Rheumatoid arthritis emerged as the most prevalent autoimmune disease, followed by psoriasis, type 1 diabetes, Grave’s disease, and autoimmune thyroiditis; 19 of the top 20 most prevalent autoimmune diseases occurred more frequently in women.

IN PRACTICE:

“Accurate data on the prevalence of autoimmune diseases as a category of disease and for individual autoimmune diseases are needed to further clinical and basic research to improve diagnosis, biomarkers, and therapies for these diseases, which significantly impact the US population,” the authors wrote.

SOURCE:

The study was led by Aaron H. Abend, Autoimmune Registry Inc., Guilford, Connecticut, and was published online on December 12, 2024,in The Journal of Clinical Investigation.

LIMITATIONS:

The use of EHR data presented several challenges, including potential inaccuracies in diagnosis codes and the possibility of missing patients with single diagnosis codes due to the two-code requirement. Certain autoimmune diseases evolve over time and involve nonspecific clinical signs and symptoms that can mimic other diseases, potentially resulting in underdiagnosis. Moreover, rare diseases lacking specific diagnosis codes may have been underrepresented.

DISCLOSURES:

The study received support from Autoimmune Registry Inc., the National Institutes of Health National Center for Advancing Translational Sciences, the National Heart, Lung, and Blood Institute, and other sources. Information on potential conflicts of interest was not disclosed.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.