Causation in medical civil liability: conceptual differences between Law and Medical Expert Assessment (factual and legal causation)

Abstract

Medical liability generally requires proof of fault, damage, and causation. In litigation involving physicians’ liability for alleged medical malpractice, expert evidence is often indispensable, since the assessment of professional conduct and the determination of the connection between the alleged act and the resulting harm demand specialized scientific and technical knowledge. However, the determination of causation encounters epistemological and semantic barriers, as Medicine and Law adopt different definitions of the same phenomenon. This article examines the conceptual divergence between the medico-legal expert approach to causation and its legal concept. It argues that medical experts tend to define causation as factual causation, based on the biological plausibility linking an event to an injury, while overlooking the fact that, in medical liability disputes, establishing a breach of the applicable standard of care is generally indispensable. In other words, the relevant causal nexus must connect a breach of the applicable standard of care to the resulting damage; a mere biological connection to an adverse outcome is insufficient. The article further contends that this terminological dissonance, when left unaddressed, may mislead courts by transforming purely pathophysiological relationships into grounds for civil liability, even in the absence of any violation of the leges artis.