Variations in Health Insurance Coverage by Age Introduction The importance of age as a disparity domain is tied to its universal marker as a component of one's identity. For anyone who seeks to understand one way by which people are different from each other, it is easy to outline segments of a population based on age. In addition, there is an accepted consensus in various academic and clinical realms (e.g. medical epidemiology, health sciences, and sociology) that functions of age are influential measures of health status.