Evaluation of the Paris and Freiburg classification scheme. Classification of the European cohort according to the Paris⁹  and the Freiburg⁸  classification schemes is shown in the bottom half of the figure. Absolute and relative numbers of patients are indicated. Percentages refer to the prevalence of the indicated clinical phenomenon in the respective subgroup of patients. Significant differences in the prevalence between subgroups are indicated (*P = .03 compared with MB2; + P = .02 compared with MB1; ‡P = .04 compared with group 1b, P < .001 compared with group 2; §P = .02 compared with group 2).