Dynamic Changes and Future Trend Forecasts in the Global Burden of Guillain–Barré Syndrome: Analysis of 204 Countries and Regions From 1990 to 2021, Including the Impact of the COVID‐19 Pandemic

BACKGROUND: Guillain-Barré syndrome (GBS) is an immune-mediated neuropathy that may be influenced by infectious, demographic, and healthcare-related factors. Although increasing attention has been paid to neurological complications during the COVID-19 pandemic, the global burden, inequalities, and future trends of GBS remain insufficiently characterized. METHODS: This population-based observational epidemiological study used data from the Global Burden of Disease Study 2021 to assess the burden of GBS across 204 countries and territories from 1990 to 2021. The main outcomes included prevalence, years lived with disability (YLDs), age-standardized prevalence rate (ASPR), age-standardized YLD rate (ASYR), and estimated annual percentage change (EAPC). Analyses were stratified by sex, age group, country, region, and socio-demographic index (SDI). Inequality analysis, decomposition analysis, Joinpoint regression, and Bayesian age-period-cohort modeling were further used to assess socioeconomic disparities, driving factors, temporal changes, and future trends. RESULTS: From 1990 to 2021, the global burden of GBS increased substantially. In 2021, the global number of prevalent cases reached 471,850, and the ASPR was 5.91 per 100,000 population. The corresponding number of YLDs was 139,639, with an ASYR of 1.75 per 100,000 population. The burden was lowest among children younger than 5 years and increased progressively with age. Males generally had a higher burden than females, particularly among older adults. Low-SDI regions experienced disproportionately higher ASPR and ASYR, indicating substantial global inequalities. The increases observed after 2019 temporally coincided with the COVID-19 pandemic; however, this association should be interpreted cautiously. Decomposition analysis suggested that epidemiological changes, population growth, and population aging collectively contributed to the increasing burden of GBS. CONCLUSION: The global burden of GBS increased markedly from 1990 to 2021, with substantial regional, sex-, age-, and SDI-related heterogeneity. The post-2019 increase temporally coincided with the COVID-19 pandemic, but causal inference should be avoided due to the observational nature of this study. Strengthening neurological surveillance, improving early diagnosis and treatment capacity, and reducing healthcare disparities in low-SDI regions may help mitigate the future burden of GBS.