Medians for the area under curve (AUC), sensitivity, and specificity for various cut points (counts/min) tested in the development sample set using Receiver Operating Characteristic (ROC) curves for accelerometer worn a waist or wrist during a ∼24-h stay in a whole-room indirect calorimeter.

Bolded values are optimal cut points for bedtime rest (CP1) and activity (CP2).
a- Area under the ROC curve calculated as sensitivity multiplied by specificity before data were rounded;
b- defined as the probability of correctly classifying bedtime rest period;
c- defined as the probability of correctly classifying activity period.