The Causation Conundrum & Commentary On Who Should Perform Causation Analysis
by Brian L. Grant, MD
A core component on independent assessment and review is determination of causation. Such determinations should be evidence based. Evidence stands on its own merits. It is not a function of the degree of the expert or the opinion of a judge, legislator, advocate or journalist.
Examples abound of such errors in causation. These include Mild Traumatic Brain Injury (MTBI). Scientific evidence is lacking to prove a relationship between MTBI and permanent impairment. Similarly, legal and administrative pronouncements that presume a relationship between hypertension and law enforcement are unsupported by solid science. The media is awash with assumed links between military service and MTBI and PTSD at alarming rates, suggesting either a slippage of criteria, or a profound change in the nature of warriors or the nature of war. Just typing the prior sentence causes this writer anxiety, lest I be accused by advocates of demeaning military service.
Psychiatrists in Washington at Madigan Army Medical Center know all too well the dangers of exercising scrutiny in the politically fraught world or military PTSD. See the accompanying blog post that addresses this.
An expert expressing an opinion is just expressing an opinion – UNLESS the opinion is supported by solid evidence and scientific facts.
The book Guides to the Evaluation of Disease and Injury Causation addresses the challenge of causation determination in-depth as well as proper protocol to determine cause. Among other insights, it discusses the challenge of relatedness; that an event preceding a complaint does not establish causation but may, in the absence of specific evidence, constitute false reasoning.
The protocol to establish causation is a six step process:
1 – Definitely establishing a diagnosis
2 – Applying relevant findings from epidemiological science to the individual case
3 – Obtain and assess the evidence of exposure
4 – Consider other relevant factors
5 – Scrutinizing the Validity of the Evidence
6 – Evaluation of the results from all of the above steps, and generation of conclusions
The above points and much more are from a seminal article, “Determining Injury-Relatedness, Work-Relatedness, and Claim Relatedness” by Robert J Barth, Ph.D. (BarthRJ. Determining Injury-Relatedness, Work-Relatedness, and Claim Relatedness. AMA Guides Newsletter.May/June 2012: 1-10.)
As of this writing, the issue of the newsletter is not yet listed on the AMA site, but presumably it will be soon and may be accessed by calling them at (800) 621-8335.
Barth is perhaps the foremost thinker and writer on this and many other related topics. The cited article is copyrighted and as such can’t be attached, but is well worth acquiring. In our opinion it is a must read and must own for anyone involved in medical or legal work involving medical causation.
We must quote another pearl from the above article that challenges the bias equation that is often applied to independent evaluators as opposed to treating clinicians:
“As is the case for any forensic work, a causation analysis should be conducted in an independent context. Treating clinicians face considerable financial and social conflicts of interest if they attempt to engage in any forensic activity (such as causation analysis) in regard to their patients. In contrast, independent evaluations minimize the evaluator’s conflicts of interest. Therefore, treating clinicians should refrain from engaging in any forensic work that involves their patients (including refraining from causation discussions).”
Clinicians not involved in the treatment of a particular claim may not be free of bias if they allow themselves to be swayed by requestors of their services. But in our experience the majority of those desiring evaluations are not overly invested in a particular outcome and more likely seek a realistic assessment of the truth, causation and related matters, in one of many cases they are managing at a given time. Contrast this to the considerable pressures that may be experienced in a treatment relationship where the emotional and economic stakes are very high for a patient, who may cause pressure to be felt by the treating clinician and impair objectivity as a result. Regardless of whether one is treating or evaluating, the same rigorous principles of causation analysis as well as other aspects of assessment, diagnosis and treatment must apply.