Fig. 2

OKS-PS cut-off point over number of clusters. Cut-off point corresponding to the upper limit of the OKS-PS distribution of the high-pain cluster. Results from the primary analysis are shown in black, obtained by applying hierarchical clustering to the original ordering of the sample. Results from the secondary analyses are shown in blue and pink, reporting ±1sd at either side of the average cut-off points derived after 100 random re-orderings of the sample. Results in blue correspond to hierarchical clustering and pink to k-means clustering