Table 1.

Key concepts.

Concept	Explanation
Expert patient	Patients who are actively involved in online communities and who share disease experiences, information, and support with other patients and develop expertise in disease self-management.
Patient advocate	Third-party users of social media who are vocal in raising awareness of illness and disease. They are a specialized type of social media influencer and are recruited by pharmaceutical companies to participate in the development and promotion of pharmaceutical products.
Digital opinion leader	Health care professionals with an active social media presence who are seen as leaders among their peers.