Assessing drug safety assessment: metformin associated lactic acidosis

Abstract

This chapter examines two approaches to assessing drug safety evidence. Method-focused approaches, such as Evidence-based Medicine, are the dominant approaches to evidence evaluation in medicine. On this approach, a body of evidence is evaluated according to the method used to generate the evidence. A second approach to evidence evaluation focuses on causal assessment. One such approach is Russo and Williamson’s account of epistemic causality. A key insight of Russo and Williamson’s approach is that causal assessment consists in seeking evidence of difference-making and evidence of mechanisms. Evidence regarding metformin-associated lactic acidosis is used to compare the advice provided by method-focused and causal assessment approaches to evidence. We argue that the context of assessing drug efficacy and safety are more different than is typically appreciated and that these differences emphasise the importance of taking a causal assessment approach to assessing drug safety evidence.