[Antibiotic prophylaxis for the prevention of infective endocarditis].

This paper argues that the National Institute for Health and Clinical Excellence should not offer guidance in situations where there is insufficient evidence equipoise about the potential benefit of the treatment in question. This is broadly for two reasons. First, without knowing if the treatment is effective no cost-effectiveness judgement can be logically made. Second, the implementation of a population wide change in treatment where there is equipoise amounts to a de facto clinical trial that falls outside the Clinical Trials Regulations. As such there are strong ethical and possibly legal grounds for preventing such an outcome. Guidance based upon insufficient evidence equipoise also impacts upon the clinical discretion possessed by individual medical professionals.