An Enigmatic Degree of Medical Certainty
by Nelson Abbott and Landon Magnusson
Every profession uses its own jargon. Psychologists describe a client’s “affect” while an acting coach describes a student’s “expression.” The use of jargon frequently causes difficulties when members of differing professions converse. For example, economists and accountants find themselves at odds over the meaning of terms like “capital” and “profit.” In the legal profession, attorneys must also converse frequently with members of other professions. Misunderstandings and problems can be especially common when meaning is lost in the translation from “legalese” to plain English. For example, when professionals are required to give opinion testimony under Utah Rules of Evidence 702, such misunderstandings may result in testimony being wrongfully admitted or improperly excluded.
This article focuses on the misunderstandings and problems that arise in situations where health care providers are requested to testify to a “reasonable degree of medical certainty.” Specifically, this article examines the origin of this problematic phraseology, how it evolved, and how it ultimately became engrained in traditional legal jargon. The article then demonstrates how the phrases “reasonable degree of medical probability” and “reasonable degree of medical certainty” adversely affect the admission of expert testimony in the courtroom, and concludes by making a case for the abandonment of these inherently flawed phrases in the law.
I. Definition, Origin, Evolution, and Usage
Attorneys have bandied about the phrase “reasonable degree of medical certainty” for years, and use it as though it is well-defined and well-understood. Unfortunately, such is not the case. Not only doctors struggle in applying the standard. Attorneys frequently struggle as well.
One of the authors of this article was in a deposition in which opposing counsel asked a physician to express his opinion regarding the likelihood that a certain event had a causal effect upon an injury. After the doctor offered his opinion, opposing counsel followed up by asking, “Can you testify to that with a reasonable degree of medical certainty?” The doctor hesitated as if he did not understand the question and was perhaps embarrassed to admit as much. At that point, the author interjected and asked opposing counsel to define the term “reasonable degree of medical certainty.” The opposing attorney hemmed and hawed and then moved on, leaving the issue unresolved. Not only was the doctor uncertain of the meaning of the phrase, but so was the opposing attorney.
Deconstructing the phrase in hopes of finding its meaning proves futile. The words “certain” and “certainty” signify being “known or proved to be true,” or, more simply, “indisputable.” Merriam-Webster’s Collegiate Dictionary 202 (11th ed. 2003). The phrase “reasonable degree,” however, implies that there is a rational choice to be made among a range of differing options. The modification of the superlative “certain” by the word “reasonable” creates a contradiction within the phrase itself. The idea that there is a reasonable degree of certainty implies that there exists an unreasonable degree of certainty, or a lesser degree of certainty, or a lesser degree of being indisputable. This begs the question, at what point does something become so “indisputable” that it becomes reasonable? Obviously there is an inherent problem in the phrase and deconstructing it does not yield any useful definition.
Black’s Law Dictionary defines “reasonable medical probability” as “a standard requiring a showing that the injury was more likely than not caused by a particular stimulus, based on the general consensus of recognized medical thought.” Black’s Law Dictionary 1273 (8th ed. 2004). Black’s treats the term “reasonable medical certainty” as a synonym of “reasonable medical probability.” Thus, Black’s seems to subscribe to the view that “reasonable degree of medical certainty” simply means that, based upon generally accepted medical principles, the statement is more likely than not to be true. The definition as stated in Black’s Law Dictionary is not universally accepted. Other sources explain the standard outlined by the phrases as “evidence from which a reasonable person could conclude that a[n action]…has probably caused a particular…kind of harm.” See Alder v. Bayer Corp., 2002 UT 115, ¶ 73, 61 P.3d 1068. Yet others define the phrases as requiring a higher degree of probability. See Michael D. Freeman, The Problem with Probability, Trial, Mar. 2006, at 58-59.
This confusion can be traced to the first appearance of the phrase “reasonable medical certainty” in Illinois case law during the 1930s. See Jeff L. Lewin, The Genesis & Evolution of Legal Uncertainty about “Reasonable Medical Certainty,” 57 Md. L. Rev. 380, 430 (1998). The cases in question involved actions in which plaintiffs claimed damages for disabilities that could have continued into the future as a result of the harm received. Id. The courts ultimately concluded that to recover for such injuries, plaintiffs needed to show with reasonable medical certainty that the disabilities would indeed continue in the future.
Since then, the ambiguity of the meaning of “medical certainty” has led to confusion and, as a result, inconsistent applications of the standard. In one Utah case, a physician was asked to provide testimony regarding the causality of an injury. The physician stated that he “did not have any reason to believe that any other incident, other than the accident” in question could have caused the plaintiff’s condition. Beard v. K-Mart Corp., 2000 UT App. 285, ¶ 19, 12 P.3d 1015, cert. denied, 20 P.3d 403 (Utah 2001) (emphasis added). The doctor’s language appears to be very clear, even using the superlative “not…any” to express his professional opinion about the matter. During cross examination, the defense asked the medical doctor about alternative possibilities and then concluded by asking the doctor if he was willing to testify that, based upon a reasonable degree of medical certainty, no other possibility could have caused the trauma. The doctor responded that he could not provide such testimony and his testimony was deemed insufficient. See id.
In a similar case in Missouri, a medical doctor testified that he was ninety percent certain as to the causality of a condition. See Bertram v. Wunning, 385 S.W.2d 803, 807 (Mo. Ct. App. 1965), appeal after remand, 417 S.W.2d 120 (Mo. Ct. App. 1967). However, despite giving this high probability, he later retreated when asked to testify as to causation of the condition with “reasonable medical certainty.” Id. In the end, notwithstanding the strong and “practically certain” testimony of the doctor, the Missouri court found the testimony to be insufficient because it lacked the “reasonable certainty” stamp of approval. Id.
While these medical professionals appeared to interpret “medical certainty” to require a very high degree of probability, others may not. Some cases even promote the contrary, stating that an “absolute,” “unqualified,” or even “scientific” certainty is not required of a medical professional’s testimony in order for it to be admitted as evidence on causality. See Sears, Roebuck, & Co. v. Workmen’s Comp. Appeal Bd., 48 Pa. Cmwlth. 161, 166-167 (Pa. 1979). In Galileo’s Revenge: Junk Science in the Courtroom, Peter W. Huber contends that a “clinician can testify to anything if he holds an M.D. and is willing to mutter some magic words about ‘reasonable medical certainty.’” Peter W. Huber, Galileo’s Revenge: Junk Science in the Courtroom, at 176 (1993).
This notion is particularly alarming in criminal cases where a verdict may result in the incarceration of the defendant. In criminal cases, the burden of proof is raised to “beyond a reasonable doubt.” But this begs the question whether the testimony offered as proof is given much more weight than is due. In a criminal case involving the sexual abuse and exploitation of a minor, a medical professional testified that “within a reasonable degree of medical certainty, it could be established that the females [on a video tape] were under the age of eighteen.” State v. Atkin, 2003 UT App. 359, ¶ 13, 80 P.3d 157 (Utah Ct. App. 2003), cert. denied, 90 P.3d 1041 (Utah 2004). By this, did the doctor mean that it was more likely than not that the females were under the age of eighteen, was the doctor stating that he was certain beyond a reasonable doubt, or was the doctor testifying that he was absolutely certain that the females were under the age of eighteen? When the jury applied the physician’s testimony to the facts of the case, it is likely that the jury gave the testimony a different weight than the doctor intended.
The Utah Supreme Court has weighed in on the definition of these phrases. In Alder v. Bayer Corp., 2002 UT 115, ¶ 73, 61 P.3d 1068, the Supreme Court stated that the phrase “reasonable degree of medical certainty” was tantamount to the phrase “a reasonable person could conclude.” Id. ¶73. It could be argued that the Utah definition requires even less certainty than the “more likely than not” standard, since a reasonable person might reach a conclusion that was not the most likely in some situations. The Utah Court of Appeals recognized that this language might create confusion stating that,
[t]he clarity of the reasonable certainty standard…has been confounded by a confusing clutter of labels, such as “in all likelihood,” “reasonably probable,” “medically probable,” “probable,” “more probable than not,” “a probability,” “more likely than not,” “greater than fifty percent,” “reasonable medical certainty,” or any combination of the above. These labels are used in an apparent attempt to shed light upon the degree of proof required of the burdened party. The net effect of this profusion of language is to leave one wondering whether the courts are discussing the same standard or standards of subtly different degrees.
Dalebout v. Union Pacific R.R. Co., 1999 UT App. 151, ¶ 21 n. 2, 980 P.2d 1194 (quoting David P.C. Ashton, Comment, Decreasing the Risks Inherent in Claims for Increased Risk of Future Disease, 43 U. Miami L. Rev. 1081, 1103-04 (1989) (footnotes omitted)).
II. The Admission of Expert Testimony in the Courtroom
In jury trials, the jury is the ultimate arbiter of fact. To fulfill their role, the jurors must weigh all of the facts as they are presented and then make their decision. In many cases, the factual issues presented to a jury can be very complex and jurors frequently lack the training and experience to properly evaluate the evidence. In such cases, jurors look to experts to provide methods and opinions or both to understand and interpret the evidence before them. See Utah R. Evid. 702. Experts assist the jury by testifying in one of two ways. First, experts may lay out scientific principles and methodology and then allow the jury to apply those principles to the facts of the case. Second, experts may apply the facts of the case to scientific principles and methodology and give opinions as to the conclusion to be drawn from the process.
Like their federal counterparts, the Utah Rules of Evidence require the trial judge to act as a “gatekeeper,” determining what expert testimony may be admitted and what testimony must be excluded. See Utah R. Evid. 702 advisory committee’s note.1 The rationale for the “gatekeeper” function of the trial judge is the assumption that an expert’s testimony may be given undue weight by members of the jury. Accordingly, the Supreme Court has held that the trial judge’s role as a “gatekeeper” of expert testimony is to ensure that the claimed basis for scientific testimony is valid. Daubert v. Merrell Dow Pharmaceuticals, Inc., 509 U.S. 579, 597 (1993).2 For example, allowing a phrenologist to give “expert” testimony may give the impression that as a witness, he or she has something credible to contribute to the case despite the fact that phrenology has long been a discredited pseudoscience. It is the court’s responsibility to recognize problematic expert testimony, and to take necessary precautions to ensure that a jury is not improperly swayed.
The Utah Supreme Court has gone even further to note that even credible scientific testimony needs to be controlled, holding that “while often helpful, scientific testimony has the potential to overawe and confuse, and even to be misused for that purpose” and it is, therefore, the court’s responsibility to “ensure the reliability and helpfulness of the evidence.” Alder v. Bayer Corp., 2002 UT 115, ¶ 56, 61 P.3d 1068. Therefore, when expert testimony is provided as an expert opinion, as opposed to testimony that merely lays out scientific principles and methodology for a jury to apply to the facts, trial judges must be especially vigilant that the ultimate trier of fact does not surrender its responsibility to an eloquent witness who provides “scientific-sounding” testimony. See Utah R. Evid. 702 advisory committee’s notes.
Ultimately, expert testimony is supposed to help and not hinder the trier of fact in reaching a proper verdict. Therefore, the testimony provided must be clear, understandable, and not likely to confuse. If testimony is not clear enough for a lay juror to understand, a judge may simply exclude that testimony. See State v. Gutierrez, 753 P.2d 501, 504 (Utah 1988). Additionally, even if testimony is relevant to an issue, if the court feels that the testimony’s probative value would be outweighed by the possibility that it would confuse and mislead the jury, the judge may also exclude that testimony. See State v. Miller, 709 P.2d 350, 353 (Utah 1985). Accord U.S. v. MacDonald, 688 F.2d 224 (4th Cir. 1982); Utah R. Evid. 403.
III. Ending the Abuse of the Phrases “Reasonable Degree of Medical Probability” and “Reasonable Degree of Medical Certainty”
Because the phrases, “reasonable degree of medical probability,” “reasonable degree of medical certainty,” and the standards they purport to embody are so poorly understood and inconsistently used, courts should prohibit their use. Because these phrases are so inconsistently used, their value is small, while the likelihood that the finder of fact will apply a definition different than the expert witness is high. In other words, use of the phrases is confusing and not helpful to the finder of fact.
In many cases, lay jurors likely give too much clout to the phrases “reasonable degree of medical certainty” and “reasonable degree of medical probability.” While the testifying physician may only mean that a reasonable person could reach the conclusion at issue, the lay jurors may assume that the physician is almost certain that his or her conclusions are correct. While one person may understand the phrases to be defined as “more likely than not” another may understand the phrase to mean eighty-five, ninety-five, or even one hundred percent certain, and lend more weight to the testimony than it deserves.
Moreover, attorneys should not assume that jurors will accord the proper weight to expert testimony framed in terms of “reasonable degree of medical certainty” or “reasonable degree of medical probability.” If faced with a medical professional who is prone to use these phrases in testifying, attorneys must determine what that specific medical professional means when using the phrases, and assist the medical professional transforming the “magic words” into more universally understood terminology to ensure that nothing is misunderstood or lost in translation. Preferably, attorneys should ensure that all expert opinions be rendered as “reasonable probabilities.” See Michael D. Freeman, The Problem with Probability, Trial, Mar. 2006, at 58-59. In other words, attorneys should find ways to compel opposing experts to compare the likelihood of the expert’s opinion with other possibilities.
In the end, the phrases “reasonable degree of medical certainty” and “reasonable degree of probability” are simply not necessary in the court room, do more harm than good, and should consequently be eliminated from the legal lexicon.
1. The advisory committee’s note indicates that the Utah rule has shadowed the federal rule in many respects as an answer to the U.S. Supreme Court’s decision in Daubert v. Merrell Dow Pharmaceuticals, Inc., 509 U.S. 579 (1993).
2. As noted above in footnote 1, the Utah Rules have been altered to better conform to the Supreme Court ruling in Daubert.