Figure 1From: Measurement of change in health status with Rasch models Rasch analyses run separately on the data from the two time points. The upper diagram depicts the item measures at Time 2 (y axis) plotted against those at Time 1 (x axis). Greater measures indicate more severe items. The identity line x = y is added for reference. The lower diagram depicts the thresholds and the probability curves of response categories at Time 1 (unbroken line) and Time 2 (broken line). “↑” points out the location of the thresholds on the latent variable.Back to article page