Fig. 2

Above: Mean-Difference Plot for the comparison of the Global Health State measured by the SOSGOQ2.0_GER and the EORTC QLQ-C30 questionnaires at baseline assessment. The thick dotted lines at the top and bottom of the figure represent the limits of agreement. Compared are 111 patients where the x-axis shows the average versus the difference of both measurements on the y-axis. Six of 111 comparisons are outside or intersect with the limits of agreement corresponding to an error slightly higher than 0.05. By chance alone we would expect 5 % background noise under the assumption that the error is normally distributed. But in advance (see material and methods) we have determined that we will tolerate a disagreement of 10 % between the measurement methods. Women and men are color-coded for representation purposes only. Below: Mean-Difference Plots for the comparison domain by domain at baseline assessment. Domain (number of patients, disagreement in percent) - Physical Functioning (113, 4.4), Pain (112, 4.5), Mental Health (111, 9.0), Social Functioning (111, 4.5). All domains were within the allowed error of 10 %