Unit of measurement centered on the patient is the most granular; and is the foundation of the units of measurement of the higher levels.

The health network offers information for queries if and only if there is definition of the entities comprising the network, who the members are, how they are linked, and how barriers are overcome to the free and transparent flow of information. Defining the network as a multifaceted channel for flow of information requires a starting point, the fundamental unit of measurement from which all data aggregation is derived, and the reference point for analysis. The fundamental level is the patient.

The network, Y, comprises the lowest scale in terms of numbers, starting from a single patient, and moves through each provider or organization as the size grows. The level above the patient is the provider, next the provider group or association; next the plan, then region, then the national scale of CMS and multistate insurance plans. For a conceptual illustration of the Patient Centered Network see Patient Journey.