A Risk Factors Screening Method in the Context-aware System of Hypertension Topics: Context-awareness and Location-awareness ; Health Informatics as a Service (HIaaS) for any Type of Health Informatics, Computation and Services; Healthcare Services and Health Informatics In Proceedings of the 4th International Conference on Internet of Things, Big Data and Security IoTBDS - Volume 1, 49-56, 2019 , Heraklion, Crete, Greece