Estimation of prevalence of autoimmune diseases in the United States using electronic health record data

Abstract

BACKGROUNDPrevious epidemiologic studies of autoimmune diseases in the US have included a limited number of diseases or used metaanalyses that rely on different data collection methods and analyses for each disease.METHODSTo estimate the prevalence of autoimmune diseases in the US, we used electronic health record data from 6 large medical systems in the US. We developed a software program using common methodology to compute the estimated prevalence of autoimmune diseases alone and in aggregate that can be readily used by other investigators to replicate or modify the analysis over time.RESULTSOur findings indicate that over 15 million people, or 4.6% of the US population, have been diagnosed with at least 1 autoimmune disease from January 1, 2011, to June 1, 2022, and 34% of those are diagnosed with more than 1 autoimmune disease. As expected, females (63% of those with autoimmune disease) were almost twice as likely as males to be diagnosed with an autoimmune disease. We identified the top 20 autoimmune diseases based on prevalence and according to sex and age.CONCLUSIONHere, we provide, for what we believe to be the first time, a large-scale prevalence estimate of autoimmune disease in the US by sex and age.FUNDINGAutoimmune Registry Inc., the National Heart Lung and Blood Institute, the National Center for Advancing Translational Sciences, the Intramural Research Program of the National Institute of Environmental Health Sciences.

Keywords: Autoimmune diseases; Autoimmunity; Epidemiology; Sex hormones.

Figure 1. A flow chart of the study design.

A total (TL) of 10,365,946 individuals were identified from the electronic health record (EHR) from January 1, 2011, to June 1, 2022, from 6 healthcare sites in the US based on a program that identified patients with 2 diagnoses codes for any disease at least 30 days apart (denominator). From this total, 581,343 individuals were identified with 1 of 105 specific autoimmune diseases (ADs) based on 2 diagnoses codes at least 30 days apart (numerator) in the EHR. Overall AD prevalence for women and men was computed based on US Census Data for 2022. The 6 healthcare sites included University of Southern California (USC), University of Florida (UF)/ Shands, Mass General Brigham (MGB), Washington University of St. Louis (WUSL), University of Iowa (UI), and the Medical College of Wisconsin (MCW). The image was designed using BioRender.

Figure 2. Prevalence of multiple autoimmune diseases.

Individuals with 1 autoimmune disease are known to often suffer from another autoimmune condition. Research strategies that count individual autoimmune diseases and then aggregate those statistics for multiple autoimmune diseases count individuals more than once and thereby might overstate prevalence. This figure reports the frequency of multiple autoimmune diseases in this study, indicating that this could be an issue in certain prevalence estimates and indicates how often they cooccur.