Abstract
Trust is a salient feature in the context of health care, which is characterized by uncertainty and an element of risk. It is a fundamental requirement for the acceptance and adoption of new services related to health care. Soft trust, based on social control mechanisms, has yielded to evidence-based trust management, where the level of trust is explicitly computed by a trust engine termed the trust and reputation system (TRS). In e-health, soft trust can be used for access control, for assessing the quality of data represented in electronic health records, to address privacy and security requirements of healthcare systems, and to compute the credibility of an entity in the presence of unknown, possibly harmful entities. Despite the importance of soft trust in healthcare, related literature that explore soft trust issues, associated challenges and requirements are largely missing. To address this defficiency, the main contributions of this paper include: (i) taxonomy related to the soft trust in healthcare systems; (ii) reference model for measuring the performance and features of TRSs; and (iii) future areas of research related to the soft trust in healthcare.