A number in circulation: HbA1c as standardized knowledge in diabetes care

In this chapter, the value HbA1c is investigated as a form of standardized knowledge in diabetes care, and the significance this form of knowledge has for a variety of practices is explored. HbA1c is discussed here as a value expressed in figures, but where the figures are interpreted, translated, and understood in different ways, depending on the practice presenting or using the figures. Ethnographic methods allow us to follow the figures and how they are discussed, whether at staff meetings or in individual clinical encounters with parents whose children have recently been diagnosed with diabetes. These are figures which can serve as a key metric in the narrative that professionals create in the clinical encounter, a narrative that emphasizes the importance of managing one’s diabetes. It can also be a narrative that visualizes developments at an endocrinology department in a national comparison with other departments’ averages for HbA1c. However, the representation of figures produced by HbA1c testing is not limited to narratives or visualizations, but is used for a wide range of quantifications, measurements, and standardizations according to the subject—doctor, nurse, patient, parent, and so on. In other words, it forms the normative guidelines to which various subjects relate differently.