10.6084/m9.figshare.5128531.v1 Benedetti M.D. Benedetti M.D. Pugliatti M. Pugliatti M. D''Alessandro R. D''Alessandro R. Beghi E. Beghi E. Chiò A. Chiò A. Logroscino G. Logroscino G. Filippini G. Filippini G. Galeotti F. Galeotti F. Massari M. Massari M. Santuccio C. Santuccio C. Supplementary Material for: A Multicentric Prospective Incidence Study of Guillain-Barré Syndrome in Italy. The ITANG Study Karger Publishers 2015 Guillain-Barré syndrome Incidence Prospective study Axonal and demyelinating GBS Trend 2015-08-29 00:00:00 Dataset https://karger.figshare.com/articles/dataset/Supplementary_Material_for_A_Multicentric_Prospective_Incidence_Study_of_Guillain-Barr_Syndrome_in_Italy_The_ITANG_Study/5128531 <b><i>Background:</i></b> To assess Guillain-Barré syndrome (GBS) incidence we relied on the Italian Network for the study of GBS (ITANG) established in 2010 in 7 Italian regions to analyse the association between influenza vaccination and GBS. <b><i>Methods:</i></b> All individuals aged ≥18 years, presenting with clinical manifestations that suggested GBS according to the universally accepted Asbury's diagnostic criteria (1990) were prospectively notified to a centralised database by ITANG neurologists over the period October 1, 2010-September 30, 2011. Through a telephone survey, 9 trained interviewers followed up the cases to diagnosis and then for 1 year since hospital discharge. Validation of case reporting was performed with the support of administrative data in 5 regions. <b><i>Results:</i></b> We found 365 cases fulfilling the definition for GBS or one of its variants over 19,846,068 population ≥18 years of age, yielding an annual incidence rate of 1.84 per 100,000 (95% CI 1.65-2.03), 2.30 (95% CI 1.99-2.60) in men and 1.41 (95% CI 1.18-1.64) in women. A highly significant peak of incidence was observed in February 2011 as compared to reference month (September 2011, rate ratio 3.3:1, p < 0.01). <b><i>Conclusions:</i></b> In Italy, GBS incidence was among the highest reported in Europe and higher than previously observed in Italian studies.