Unpacking the process of interpretation in evidence-based decision making.

Abstract

Evidence-based medicine (EBM) has promoted the conscientious and systematic use of the best available scientific evidence in clinical decision making [1]. From an EBM point of view, only experimental evidence, especially results from randomized controlled trials and meta-analyses of trial results, count as strong evidence. Experiential evidence based upon expert opinion is classified as weak and placed at the bottom of the evidence hierarchy. EBM is often contrasted with traditional clinical medicine which considered pathophysiological reasoning and expert knowledge as the principal sources of clinical decision making. In a recently published article in Journal of Evaluation in Clinical Practice, Jeannette Hofmeijer describes EBM as a revision of medical epistemology and points to the neglected role of expert opinion and the lack of focus on the principles of reasoning underpinning EMB [2]. More specifically, she shows how EBM involves important processes of interpretation. Hofmeijer is mainly concerned with the role of interpretation in the production of scientific knowledge within the EBM tradition, and she illustrates how the quest for evidence relies upon interpretation both in formulating a hypothesis and in accepting the accumulated evidence as sufficient. We will argue a related but still different perspective demonstrating the principles of reasoning involved in the integration of experimental and experiential knowledge in clinical decisions and the role of interpretation in this respect. The goal of EBM is, according to Sackett et al., the integration of (1) clinical experience and expertise; (2) scientific evidence; and (3) patient values and preferences to provide high-quality services [1]. However, a weakness of EBM is the lack of guidance on how to combine the main knowledge components of the model. The EBM literature says little about how to create a fruitful interaction between research, clinical expertise and patient preferences. Although the principal aim of EBM is to promote more conscientious and systematic clinical decision making, an important element of the model remains black boxed: the principles of reasoning according to which the different knowledge sources are combined. This paper aims to make explicit the often implicit interpretational work involved when scientific evidence, clinical expertise and patient preferences are combined. We believe that better awareness about this process of interpretation can promote better and more trustworthy decision making. Lack of individualization is a recurrent criticism against EBM [3,4]. Randomized clinical trials measure average effects and do not necessarily match the local and complex situation of the individual patient [5]. The need for a situated, practice-based reasoning has been argued, and concepts such as clinical intuition [6], tacit knowledge [7], wisdom [8] and collectively defined ‘mind lines’ [9] have been introduced to challenge a unilateral focus on implementing research evidence. More recently, the literature on patient-centred medicine and shared decision making has emphasized the importance of involving patients in medical decisions and suggested useful methods and approaches [10,11]. In spite of these attempts, the principles of reasoning according to which the knowledge sources are combined and applied are still poorly understood. There are few, if any, models and concepts available which make explicit the interpretational operations involved when combining and applying the knowledge components. We intend to throw light on this process by drawing on a four-step model of knowing developed by the Canadian philosopher Bernard Lonergan [12].