A method of determining a state of progression in a subject of a disease ortreatment having motion symptom comprisesobtaining a time series of motion data from a motion detector worn on anextremity of the subject, over an extended period during usualactivities of the subject; processing the motion data to produce a pluralityof measures of kinetic state of the subject at a respectiveplurality of times throughout the extended period, each measure of kineticstate comprising at least one of: a measure for bradykinesia,and a measure for dyskinesia; determining a measure of dispersion of themeasures of kinetic state; combining the measure of dispersionwith at least one other data characteristic determined from the motion data,to produce a selection score; and generating an outputindicating the selection score.