For citation purposes: Freeman MD, Cahn PJ, Franklin FA. Applied Forensic Epidemiology, Part 1: Medical Negligence OA Epidemiology 2014 Jan 18;2(1):2.


Methods Development

Applied forensic epidemiology, part 1: medical negligence

MD Freeman, PJ Cahn, FA Franklin

Authors affiliations

(1) Oregon Health & Science University School of Medicine, Departments of Public Health & Preventive Medicine and Psychiatry, Portland, Oregon, USA

(2) Forensic Research & Analysis, Portland, Oregon, USA

* Corresponding author Email:



The evaluation of the causal relationship between an alleged act of medical negligence and an adverse health outcome is an essential element of a medical malpractice legal action. In such an action, the question of causation is also known as the “but-for” question; i.e. but for the negligent act, would the plaintiff still have suffered the adverse outcome at the same point in time? Forensic epidemiology provides a systematic approach to the investigation of causation, with conclusions suitable for presentation in a medicolegal setting. Such an evaluation relies on the following steps: (1) the application of the Hill criteria to first arrive at a conclusion that an investigated negligent action was a plausible cause of an adverse outcome; (2) an assessment of the temporo-spatial relationship between the negligent action and the first indication of the adverse outcome and (3) quantification of the probability of causation via an estimate of the risk of injury associated with negligent action versus the risk of known contemporaneous alternative causes of the adverse outcome. In this first of a three-part series on applied forensic epidemiology, we demonstrate forensic epidemiology methods with a description of the investigation of the probability of causation in three cases of serious neurologic injury following an alleged act of medical negligence.


Causation in cases of alleged medical malpractice is commonly disputed. In cases in which direct specific causation is not a viable alternative (i.e. the diagnosis can have multiple causes), the indirect evaluation of specific causation via the methods described in this article provides a reliable methodologic framework for the quantification of the probability of causation suitable for presentation in a court of law.

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