In the Observation profile, it may help implementers if there were a discussion of the use of .effective[x]. How should this be populated and does that vary based on the type of Observation. For example, for Hunger Vital Signs, if the patient answers  questions 88122-7 and 88123-5, does .effective reflect when the question was answered for the patient, or the range of time that the patient had the concerns expressed by the patient (which presumably pre-date the answering of the questions). For the calculated risk (88124-3), is .effective the date of the calculation or the time period the patient was at risk (which again, presumably preceded the calculation of the risk). Please clarify the use of this element.