Increasing Incidence of Guillain-Barré Syndrome in the United States among Integrated Delivery Systems from 2017 to 2023: Trends by Age and Charlson Comorbidity Index Score

Introduction: Guillain-Barré syndrome (GBS) is a heterogeneous and rapidly progressive immune-mediated neurologic condition. Recent national estimates of GBS epidemiology are lacking. This real-world study describes GBS incidence trends in the United States from 2017–2023. Methods: This was an observational, retrospective, descriptive, US-based cohort study among adults who had ≥12 months of activity within integrated delivery systems of the US-based Optum’s de-identified Market Clarity Data (Optum® Market Clarity), which links electronic health records and claims. The primary GBS case definition was an International Classification of Diseases, Tenth Revision, Clinical Modification G61.0 code associated with an inpatient visit. Results: Yearly GBS incidence in adults ranged from 3.1/100,000 person-years (PY) in 2017 to 6.4/100,000 PY in 2023. In the descriptive stratified analyses, GBS incidence was higher among individuals ≥60 years old (4.0–7.3/100,000 PY) than among those <60 years (2.6–5.7/100,000 PY) and among those with Charlson Comorbidity Index (CCI) scores ≥2 (6.5–9.7/100,000 PY) compared with those with CCI scores <2 (2.6–5.6/100,000 PY). More than half of GBS patients had acute respiratory illness within 42 days before GBS diagnosis, and approximately 60% had chronic medical conditions that predisposed them to severe illness from respiratory viruses. Of note, across all analyses, the yearly number of Optum® Market Clarity subjects decreased over the study period from 37.4 million in 2017 and 3.8 million in 2023, resulting in a reduced eligible denominator for identifying GBS patients. Conclusion: This descriptive analysis reports changing epidemiology of GBS in the United States, where incidence rates may be increasing over time, and individuals with underlying comorbidities and previous infection had higher incidence of GBS. These findings help the current understanding of US GBS epidemiology, which is important for identifying individuals at risk and may contribute to improved patient outcomes through timely diagnosis and management. However, these findings should be interpreted with caution given the descriptive nature of the analysis and the absence of formal statistical testing.