1. An electronic device for outputting a signal according to at least one control parameter value of a patient, comprising: a data recording device configured to receive a first disease control parameter value; a memory comprising one or more optimal disease control parameter values, one or more self-care values of the patient, one or more optimal self-care values and one or more scaling factors; a microprocessor, in communication with the data recording device and the memory, programmed to calculate a value based upon the one or more self-care values, the one or more optimal disease control parameter values and the scaling factors; a display configured to display information according to the calculated value, wherein the information displayed enables the patient to select appropriate self care actions and the disease control parameter values are related to the patient self-care of a chronic or persistent condition being managed by the patient.