I am an academic cardiologist whose major research interest is echocardiography and whose entire 35-year career has been spent in Northern California at one institution. My extracurricular career as an expert witness began when my department chairman asked me to help his neighbour, an attorney who was representing a plaintiff and seeking an expert. The pivotal issue was whether liability for a fatal myocardial infarction was attributable to overly aggressive thyroid hormone replacement. It was my opinion that, based on the information contained in the medical records and the current pharmacological parameters, the treating doctor had not prescribed appropriately. The defence witness was a pathologist who stated that “It was only a small infarction and should not have killed him.” In deposition, my response cited a substantial body of indisputable scientific evidence supporting the lethality of acute coronary syndromes. Having no counter argument, the defence settled for an undisclosed sum.

From that time, I have been riveted by the interface between law and medicine and have since served as an expert witness at least a 100 times. The cases I have reviewed represent only a fraction of the number of requests received. Time constraints and my interest in particular cases have been the major factors limiting my involvement. While I prefer to testify in defence of my fellow doctors, about 40% of the time I have been retained by a plaintiff’s attorney. My professional opinion is not swayed by whichever “side” retains me.

My approach reflects the system used in the United Kingdom, where the duty of the expert is solely to the court. Yet, before reading the impressions of Professor Roger Hall,1 Dr Steven J D Brecker2 and Adrian Whitfield QC,3 I was unaware of the responsibilities of an expert witness in what we in America …