Medical decision-making in membranous nephropathy: how to use limited clinical research evidence in patient management

Evidence-based medicine (EBM) originally referred to the use of a combination of clinical expertise and research evidence to make medical decisions, while carefully considering the patient's preference. In Japan, however, EBM has been misunderstood as the more abstract pursuit of acquiring research evidence and building medical guidelines. This review aims to summarize the available data regarding therapy for membranous nephropathy (MN), a field in which no consensus has been reached, and to discuss medical decision-making by using a decision tree in several model cases. In clinical practice, we have to consider both the risks and benefits of treatment. These are evaluated by their therapeutic effect (the rate of improvement, no change, or worsening) and by the patients' quality of life (QOL). This process is compatible with the essential concept of EBM.