A method of determining a state of progression in a subject of a disease or treatment having motion symptom comprises obtaining a time series of motion data from a motion detector worn on an extremity of the subject, over an extended period during usual activities of the subject； processing the motion data to produce a plurality of measures of kinetic state of the subject at a respective plurality of times throughout the extended period, each measure of kinetic state comprising at least one of: a measure for bradykinesia, and a measure for dyskinesia； determining a measure of dispersion of the measures of kinetic state； combining the measure of dispersion with at least one other data characteristic determined from the motion data, to produce a selection score； and generating an output indicating the selection score.
