Systems and methods for determining whether an involuntary voiding event was attributable to stress or urge incontinence include determining an activity level of a patient that coincides with the occurrence of the involuntary voiding event or the activity level within a certain time range of the involuntary voiding event. Patient activity data may be collected via a signal that varies as a function of patient activity. The signal may be generated with one or more sensors that detect motion, such as an accelerometer or a piezoelectric crystal, and/or one or more sensors that monitor a physiological parameter of the patient that varies as a function of patient activity, such as heart rate, respiratory rate, electrocardiogram morphology, respiration rate, respiratory volume, core temperature, muscular activity level or subcutaneous temperature of the patient.