Fig. 1

Overview over study procedure. The study was conducted among all MG patients in Norway and the contiguous regions of South- and North Holland in the Netherlands, including an additional MuSK Sample from entire Netherlands. The case identification and inclusion criteria were the same in both countries. The case search in the Norwegian study area was performed nationwide including 4 university clinics, 15 local clinics and 11 private clinics. Recruitment started: 01.01.2008. Recruitment stopped: 01.11.2009. The case search in the Dutch study was conducted in two regions and the affiliation to the geographical area was defined by postal code. The area had 4 university clinics, 25 local clinics and one private clinic. Recruitment started: 01.10.2011. Recruitment stopped: 01.01.2012. 43 patients were not eligible for questionnaire study because of change of address, dementia and other co-morbidities and delay in registration of ICD-code. Abbreviations: ICD = international classification diagnosis. F: M = female: male ratio