Defining the concept and clinical features of Epistemic Trust: a Delphi study

Early identification of ‘patients at risk’ for not completing regular treatment or not benefitting (sufficiently) might be among the most cost-effective strategies in mental health care. In an earlier paper (Knapen, Hutsebaut, van Diemen & Beekman, 2019), we introduced the potential value of the concept of epistemic trust (ET) as a measurable predictor or ‘psychomarker’ of treatment outcome. This value of ET may not only be limited to mental health treatment, but to any social intervention that depends on trust in others. In order to be able to measure ET as a potential psychomarker, it becomes necessary to render the concept of ET accessible for assessment. A clinically feasible way to assess ET would be to rely upon patients self-report, by designing questionnaires that represent clinical features of ET. For this, consensus is needed on the definition and clinical features of ET. We therefore conducted a Delphi study to reach consensus on the definition of epistemic trust and its characteristics. The Delphi method is a consensus-building technique using expert opinion to formulate a shared framework for understanding a topic or theoretical concept with limited empirical support. In this paper we define epistemic trust by describing its core domains based on consensus of expert opinion on the concept. Based on this, we aim to develop items for a new self-report questionnaire to assess ET