A method of evaluating glycemic control of a patient includes providing a pentagon having five axes radiating from a center of the pentagon. A first pentagon area formed by a first point, a second point, a third point, a fourth point, and a fifth point plotted on the five axes, respectively, is determined. A second pentagon area formed by a sixth point, a seventh point, an eighth point, a ninth point, and a tenth point plotted on the five axes, respectively, is determined. A glycemic control parameter is determined based on the first pentagon area and the second pentagon area.
