Fig. 4

Discriminant validity for the behaviour, activity, and posture classification. Kappa (left) error bars denote the 95% confidence interval of commonly used counts-per-minute (cpm) cut-points. The dotted lines show the ROC curves (right) for lower (down to 0) and higher cut-points (up to 500 and 750 for waist VA and VM and 15′000 for wrist VM). Definition of behaviour, activity level, and posture is given in Table 1