What Medical Expert Witnesses Don’t Understand

First published in The Lawyers Weekly January 23, 2004, Vol. 23, No.35

I frequently see expert reports that are medically sound but peppered with elementary legal errors. Some of the writers are clinically eminent but legally naive.

Litigators may need to school and instruct medical expert witnesses in a number of the following areas that can be foreign territory for practising doctors and surgeons.

With few exceptions (epidemiologists and pathologists), clinicians are not concerned with causation. They rarely think about Why, and are instead preoccupied with What and How. Although theorising why this particular patient developed this particular expression of a disease may be intellectually stimulating, it has no practical relevance to diagnosis, management and prognosis.

Even academic physicians may need to be explicitly asked to include references to clinical research in their written reports. Examples from the teacher’s own limited clinical experience is of interest and value to medical students, but the more universal conclusions in clinical review research are of greater relevance to litigation.

In the world of diagnosis, "But For" is particularly foreign. While it is a given that medical causation is multifactorial, clinicians in their day-to-day work have no reason to speculate on what would happen if one causal factor was missing.

The range of possible outcomes is so wide that a medical expert simply cannot tell you what would have been the course of the diabetes or coronary artery disease if the personal injury had not occurred.

Occasionally there will be medical reasons for posing such a research question and answering it in a scientific paper, but generally medical expert opinion will be no more than an educated guess. Some experts will decline to make such a guess.

Scientific probability is much closer to the criminal level of "beyond reasonable doubt" than to the 50.5% likelihood that is required for civil litigation. Even when asked to select the most likely scenario, physicians often balk, for fear they will be challenged to justify their choice as a scientific certainty.

Treating physicians and Independent Medical Examiners for the claimant often fail to review contemporaneous records to validate a patient’s time-line of symptoms. They commonly construct causal relationships without allowing for recall bias - which is a universal human foible.

I frequently read expert opinions on causation that depend almost solely on a claimant’s biased recall. An internist confidently diagnosed reactive arthritis following personal injury. Cursory review of the contemporaneous clinical records showed that the first complaints appeared 8 months after the MVA, not within the 2 weeks that the claimant recalled and reported.

Caregivers often uncritically accept a previous diagnosis. A label may have been attached to a patient’s medical condition but the diagnostic evidence is not immediately to hand. Subsequent treating physicians will generally assume that this is a diagnosis that is appropriately supported by history, examination, laboratory tests and diagnostic imaging.

At times such assumption is not justified. Only when interim evolution of an illness raises doubt is the adequacy of the previous diagnostic process brought into question.

When they are medicolegally untutored, medical expert witnesses demonstrate defence-bias most clearly when they assume that an examination took place even though it was not recorded. I have seen medical expert witnesses try to argue that, because a defendant physician came to a confident diagnosis, s/he probably undertook the appropriate examination, even though such examination is not documented.

Medical expert witnesses on both sides need to be instructed that the medical malpractice default assumption is, "if it is not in the record, it didn’t happen".

but not Substandard. When asked to provide expert opinion, some physicians may give an opinion that, even though they would not call it substandard, the care the defendant provided was not the best.

Litigators shake their heads in disbelief, imagining the raucous laughter if they offered such a defence when sued for legal negligence. However, medicine is not an exact science, and there are often different ways of managing a given clinical problem. Whether one way is better than another may be a judgment call. Even if most reviewing physicians would agree that a minority approach is inferior, the medical expert witness may yet balk at dubbing it "substandard".

Be that as it may, medicolegal physicians need to understand that "suboptimal" has no useful meaning in the medical malpractice context.

A difficult transition that some medical expert witnesses fail to make. The clinical specialist has developed an expert report because he believes in the client’s position and enjoys making money by writing legal reports. In providing testimony, this witness must now switch gears, ungrudgingly acknowledge the strengths of the other side, and dispassionately help the Court understand the medical issues.

Medical experts generally understand that the court system is adversarial, but not always that physicians who act as a client’s advocate discredit themselves as expert witnesses.

When talking to their patients, most practising physicians explain medicalese by using yet more medical jargon. When writing their reports, most medical expert witnesses do the same. Rare is the medical specialist who fluently explains in plain language "on the fly".

While it is true that many medical concepts are too complex for grade seven reading level, this should arguably be a goal of reports for trials in which jurors might have to grapple with the medical issues.

These are some of the areas in which medical training and practice are at odds with medicolegal requirements. Physicians who are naive in legal medicine may need a few hours of expert witness preparation, particularly for court testimony. While litigators usually undertake such witness preparation one-to-one and face-to-face, some medical experts may prefer to digest the majority of the legal concepts from written material.

Whatever the teaching format, the clinical specialist who is beginning to provide expert witness services needs to learn the rudiments of legal medicine.