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How to Utilize a Medical Expert and Effectively Present Causation Opinions

February 17, 2017 (6 min read)

The seminal causation paper will never be written. This fact provides the author at least some comfort as this paper briefly wades into the agenda-driven minefield of causation in a workers’ compensation claim.

Causation, like beauty, is often in the eye of the beholder. The beholder in a workers’ compensation claim might be a doctor, adjuster, lawyer, or the ultimate fact-finder. Each of these groups has sub-groups with competing interests: treating v. IME doctor, plaintiff v. employer lawyer, liberal v. conservative judge, etc.

The effective practitioner must persuade the fact finder that the mechanism of injury caused a particular injury or diagnosis using that jurisdiction’s legal tests.

(Publisher's Note: The key takeaways in this article were part of a presentation by Mr. Colburn at the National Workers' Compensation & Disability Conference last year.)

I. Causation Starts with the Proper Diagnosis

Diagnostic tests are the quintessential example of objective, and therefore reliable, evidence of at least what the injury is, even if the parties disagree about causation.

False positives and negatives proliferate. In a study published in the December 2016 issue of The Spine Journal (, a patient was sent to 10 different MRI facilities. None of the 10 interpretations identified the true diagnostic finding. Another study revealed a 43.6% diagnostic miss rate. (The Spine Journal, Vol. 15, Issue 10, p2122–2125)

Consistency and accuracy are not the only concern; biases and prejudices influence doctors’ opinions. Most MRI findings are on a continuum between acute and chronic. Thus, a doctor can shade an opinion with selective phrasing (or outright omission).

MRI films are merely snapshots. Clinical examinations provide the diagnosis. An MRI should only be used to confirm that diagnosis. But some providers are misled or overly-influenced by an MRI interpretation resulting in needless treatment and surgery. There is no such thing as a normal exam. Clinicians must determine which findings are diagnostically and clinically relevant.

Multiple professionals should interpret diagnostic tests for accuracy and consistency with the patient’s symptomology. An accurate diagnosis is the first step in a proper causation analysis.

II. Causation From the Medical Perspective

Education trains the brain to think a certain way. A student’s mental approach changes after spending a year in law school, medical school, or seminary. Medical training focuses on treatment rather than causation. Legal education starts with “cause-in-fact” and “proximate” cause. Doctors want to practice medicine. Causality is a secondary concern.

The scientific community does not ignore causality. New scientific evidence may challenge the prevailing medical knowledge. Everyone “knew” that stress caused ulcers or that typing caused carpal tunnel syndrome until more research was published. But research published next year may reverse this year’s latest best evidence.

And there is the agenda. Many doctors are business people who own facilities or participate in IME work. Such doctors supplement their living based on a particular medical viewpoint. Both injured workers and employers/carriers retain experts who share a particular viewpoint for a medical causation opinion.

Legal systems once provided great deference to the causation opinions proffered by the medical community. Due to perceived “junk science”, courts now more rigorously review the expert and the expert opinion. So the “Battle of the Experts” is both personality-driven and fact-driven.

The legal practitioner must evaluate all experts and their expert opinions for credibility before the fact finder (judge or jury) and the appellate courts. The following checklist is useful for the workers’ compensation participant when evaluating the causation opinion:


> Evidence-based or consensus-based

> Well-settled or ever-changing

> New research (and quality of that research) v. old or no research


> Evaluation of the researcher (if applicable)

> Biases and prejudices

> Qualifications, generally

> Qualified to give an opinion on this topic

> Role of the expert (peer, treating, IME)

> Relative effectiveness when compared to the opposing sides’ expert

Causation Opinion

> Quality of the written report

> Quality of the opinion

> Well-reasoned or conclusive

> Based on correct mechanism of injury

> Considered all relevant evidence

> Describes how mechanism of injury caused injury/illness within the legal framework of the jurisdiction

Effective communication

> Ability to communicate (and survive attacks)

> Describe how other expert’s opinions are flawed

> Opinion is believable

> The expert is perceived as credible

Don’t pick experts just because their opinion agrees with your side. The fact-finder is your audience. Evaluate all causation opinions cognizant of your jurisdiction’s laws and culture.

III. Jurisdiction’s Laws and Culture

A legal system is best viewed as an individual, living, complex entity. Those foreign to a particular jurisdiction lack the experience to understand its nuance and subtleties. The laws matter. But the law’s development/interpretation over time form a unique culture. Different cultures persist within a jurisdiction (think Los Angeles area compared to Northern California) resulting in a different legal culture. And of course different judges bring their own biases and prejudices. Legislative reforms, the court’s response to those reforms, and the ultimate decisions made in individual cases are superimposed on this culture.

Legislatures/courts create or change their legal tests (proximate cause, producing cause, but-for cause, major contributing cause, intervening cause, etc.). Tests can also be strengthened for particular injures (for example, heart attack, psyche, etc.) or weakened/removed (think presumptions in favor of first responders). Legislative changes to the legal tests generally change outcomes unless mitigated by the regulatory body or judiciary in sweeping pronouncements (ruling changes unconstitutional) or finding subtle but frequent distinctions/exceptions. Oklahoma and Florida are just the latest examples of the reticence of regulators or the courts to change their perception of how the law ought to perform.

Know a jurisdiction’s laws and culture when presenting causation opinions to the fact-finder.

IV. Effective Presentation of Causation Opinions

Judges are rational human beings mentally trained to follow the law. But all human beings are flawed, moved by emotion, biases and prejudices. Great judges write decisions they personally disagreed with because they are following the law. But legal practitioners will rue the day they rely on such legal deference to the law.

We all have a moral value system differing mostly on how we rank and order certain values on a continuum. Conservative judges may value rules, law and order higher than other values. Conversely, liberal judges are more likely moved by fairness or justice. All judges value rules, law and order, fairness, and justice. But the order in which judges rank their values forms their moral value system and explains the worldview they use to make decisions.

People (and perhaps especially judges) are rarely persuaded to change their moral value system. Instead, structure your arguments to convince the judge that your causation opinion is most closely associated with the values the judge holds in highest esteem. A practitioner most effectively persuades the fact finder on causation when their expert’s causation opinion is more closely tied to the decision-maker’s moral value.

After you identify the most persuasive values for your particular case and your particular fact finder, make sure you have the most effective causation report in evidence using the checklist above. Repeat your trial themes, moral values, and causation opinions in pretrial, opening statements, examinations of witnesses, and closing.

V. Conclusion

Workers’ compensation insurance should pay all benefits owed – no more, no less. Paying too much will cause the system to fail; paying too little will cause individual workers and their families to suffer greatly while some of the costs are passed on to society as a whole. First, insist on an accurate diagnosis. Second, ask a qualified expert whether the mechanism of injury caused that diagnosis using the jurisdiction’s legal test. Finally, persuasively weave your expert’s opinion into the fact finder’s moral value system, understanding the jurisdiction’s legal culture.

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