When healthcare providers begin using patient-reported outcome measures at the point of care, most are surprised by the degree of discordance between anatomic explanations for a patient’s symptoms and how the patient believes he/she is able to fare with the symptoms. It is a learning process that leads to an understanding that successfully medicating, repairing, or replacing the anatomic or physiologic finding may or may not change the patient’s perception of their health, or sense of physical and mental well-being. An individual patient’s reported measures can inform the communication between patient and provider, helping them both identify and discuss what matters most to the patient so they can align treatment with the patient’s preferences and priorities. This accelerates both the process of identifying what matters most to the patient and that of creating a treatment plan that addresses those concerns. When used over time, these data help to focus discussions around what matters most and whether the treatment plan is working as expected. Chapter 1 presents the history and evolution of patient-reported outcomes, along with the business and clinical rationales driving the emergent use of such data in today’s value-based healthcare system.