To identify a MedicationDispense that has been cancelled for a reason, we assume we should use MedicationDispense.status = cancelled (perhaps declined if the patient declined) with a MedicationDispense.statusReason indicating the reason for cancelling. However, there is no method to determine when the status changed. This use case comes up in quality measures wish to determine medications for which dispensing events were cancelled for valid reasons. Therefore, a timing element such as statusChange (dateTime) is required. Request this additional element.