The epidemiology of Guillain-Barré syndrome in Thailand over 13 years (2005-2017): A nationwide population-based retrospective cohort study.

There have been no published studies examining the epidemiology of Guillain-Barré syndrome (GBS) in large populations in Thailand. This study aimed to explore the incidence, patient characteristics, seasonality, treatments, and outcomes of GBS in Thailand. The National Health Security Office (NHSO) provided data on in-patient admission between fiscal year 2005 and 2017. We selected all patients with a primary diagnosis of GBS. We retrieved data regarding the total population from the Department of Provincial Administration. A total of 4521 patients with GBS were included. The median age was 42 years (IQR 22-56), and 61.5% were male. The incidence rate increased from 0.48 to 0.93 per 100 000 population over the 13 years. The incidence was increased with age and a male-to-female ratio of 1.6:1. There was seasonal variation in the rate of admission for GBS, with significantly more patients admitted in rainy vs summer (IRR 1.94, 95%CI 1.80-2.10, P < .001) and winter vs summer (IRR 1.48, 95%CI 1.36-1.60, P < .001). Treatment with IVIg increased from 4.4% to 29.6% (P < .001), whereas plasmapheresis decreased significantly from 4% to 1.32% (P = .017). The mortality rate was 3.5%. Elderly and young adults had a significantly higher mortality rate when compared to children and teenagers (P < .001 and P = .003). The incidence of GBS in Thailand was steady over 13 years and was greater in rainy and winter season. Treatment with IVIg increased while plasmapheresis decreased. Mortality was higher in elderly patients.