Any digital health solution (that is accessible to citizens who may be patients or their informal caregivers, from home/work or elsewhere) which allows direct or indirect interaction with healthcare professionals. These include solutions that support telehealth services, whether they provide synchronous or asynchronous communication.   Fonseca, Raquel; Franco, Rafael; Jacinto, Samuel; Martins, Diogo; Silva, Nuno (2020). Guide for scaling-up digital solutions for citizen-healthcare provider interaction [pdf]. Digital Health Europe. Version 1.0.