A method of administering insulin includes receiving scheduled glucose time intervals and obtaining glucose data of a patient that includes glucose measurements, glucose times, and insulin dosages previously administered by the patient. The method also includes applying a set of filters to identify which of the glucose measurements associated with at least one of the scheduled time intervals are usable and which of the glucose measurements associated with the at least one scheduled time interval are unusable. The method also includes aggregating the glucose measurements associated with the at least one scheduled time interval identified as usable to determine a representative aggregate glucose measurement and determining a next recommended insulin dosage for the patient based on the representative aggregate glucose measurement and the insulin dosages previously administered by the patient.