Date of ISAC Approval:
Guillain-Barre syndrome (GBS) is an autoimmune disease: one's own immune system attacks part of the peripheral nervous system. When immune cells destroy the myelin layer covering the connecting links between the nerve cells (i.e. axons), the nerves can no longer transmit signals efficiently, leading to the inability of the muscles to respond to the brain's commands. In rare cases this can become life threatening by interference with breathing, blood pressure or heart rate. GBS is rare, afflicting roughly one person in 100,000, affecting men slightly more frequently than women, and becoming more frequent with increasing age. Usually GBS occurs after the patient suffered from a viral or bacterial infection, although in rare occasions vaccination may precede GBS. The objective of this study is to estimate incidence rates of GBS in the UK population based on anonymised data in the Clinical Practice Research Datalink, between April 1st, 2005 and March 31st, 2015, by six-month months periods from April to September, and October to March. This study will thus provide a baseline frequency of GBS in the population to shed light on seasonal winter to summer variations in GBS occurrence, and help evaluate potential safety signals of health interventions, including medicines or vaccines.
Knowledge of background incidence rates in the general population is key to assess adverse events suspected to be associated with health interventions. As the seasonality of Guillain-Barre syndrome (GBS) is not well understood, large epidemiological databases are a potential resource to better understand rates and seasonal variations of GBS. The objective of this study is to determine the incidence rates and seasonality of GBS in the UK general population. This is a cohort database study based on the number of cases of GBS and total person-time at risk from April 2005 to March 2015 in the UK CPRD and inpatient HES. Person-time at risk will be calculated for all subjects with censoring applied at the time of death, date of diagnosis, disenrollment from the medical practice or last collection date. Cases of GBS are defined as those subjects for whom an incident event of GBS was recorded using READ or ICD-10 diagnostic codes. Analysis: Incidence rates with 95% confidence intervals, by age group, gender, geographical region and study season (October to March; April to September). The season 1st October 2014- 31st March 2015 will be compared to prior winter seasons by estimating the incidence rate ratio and 95% confidence intervals.
Health Outcomes to be Measured:
Incidence of Guillain-Barre Syndrome cases
Dr Germano Ferreira - Chief Investigator - Not from an Organisation
Ms Kaatje (Kaat) Bollaerts - Researcher - P95
Dr Thomas Verstraeten - Researcher - P95
Mr Tom Cattaert - Researcher - P95