In complex litigation, cases are often won or lost based on who wins the "battle of the experts." Yet, one of the main weapons that experts use for "battle" in the medical and scientific arenas--scientific and medical literature--is often notably absent in Florida courtrooms. Not only are juries deprived of citation to literature because of its status in Florida as "hearsay," but judges have been reluctant to look to literature as a means of disallowing expert opinion testimony when that testimony is based on pure opinion.
Imagine the following scenario: A world renowned oncologist makes a presentation to a committee of oncologists that based on his years of treating cancer patients, he believes exposure to chemical X causes cancer. Yet, this oncologist has absolutely no scientific studies to present in support of his opinion. Rather, the oncologist has treated thousands of cancer patients who were exposed to X, and he believes that there must be a causal link between their exposure and their cancer. While many of us might view this opinion as a suggestion for someone to study the issue more thoroughly, few of us would likely rely on the opinion of one oncologist as proving that exposure to X causes cancer.
As absurd as this hypothetical may seem, this is just the type of opinion that Florida courts have held admissible based on the "pure opinion doctrine." Thus, determining whether such an opinion supports a conclusion that X causes cancer--while not a question we would expect expert oncologists to evaluate--is often a question that we ask lay jurors to decide. If this same oncologist were retained as an expert witness by a plaintiff who was exposed to X and developed cancer (or by a defendant who is claiming that X was the alternative cause of plaintiff's cancer as opposed to some exposure attributable to his client), and the oncologist formed the opinion that X caused plaintiff's cancer, then, under the pure opinion doctrine in Florida, this oncologist may very well be permitted to testify at trial regarding his opinions.
The lawyer confronting such an expert typically would have three angles of attack: 1) Try to get the court to exclude the expert's testimony; 2) cross-examine the expert on the lack of a basis for the opinion; 3) utilize the attorney's own expert to explain why this opinion is incorrect. For each of these modes of attack, the most powerful weapon is the fact that the opposing expert's opinion has no basis in scientific or medical literature.
Yet, each of these chosen avenues of attack is littered with obstacles. First, Florida case law regarding pure opinion testimony may make the lack of literature irrelevant in an attempt to exclude the expert. Second, a question on cross-examination asking the witness about the lack of literature could very well elicit the following unhelpful answer, "I didn't even bother to look for literature. I have been practicing medicine for over 30 years and I have seen exposure to X cause cancer in hundreds of my patients. I don't know if there is any literature on this; I just know it to be true based on my own clinical experience." Third, recent case law interpreting the rule against "bolstering" can be read to prohibit using your own expert to testify regarding the lack of scientific literature on a given topic.
Obstacles to Confronting Pure Opinion Testimony in Florida
Florida courts have defined "pure opinion" testimony as an expert opinion that is based on the expert's "personal experience and training." (1) In Holy Cross Hospital, Inc. v. Marrone, 816 So.2d 1113 (Fla. 4th DCA 2001), the Fourth District articulated the difference between expert opinions admissible under the pure opinion doctrine and those that are subject to a Frye analysis: Pure opinion refers to expert opinion developed from inductive reasoning based on the experts' own experience, observation, or research, whereas the Frye test applies when an expert witness reaches the conclusion by deduction, from applying new and novel scientific principle, formula, or procedure developed by others.
In some ways, the distinction between opinions that must meet the Frye (2) test and those that are based on pure opinion seems counterintuitive and potentially counterproductive. If an expert witness dares to utilize scientific literature as a tool in helping form an opinion, then the court can and will scrutinize that opinion under Frye. In Holy Cross, for example, the Fourth District held that an expert's opinion regarding when a patient's cancer spread to the lymph nodes was subject to a Frye analysis because the expert relied on cancer staging studies in forming his opinion. (3) Yet, employing the analysis articulated by the Holy Cross court also leads to the conclusion that if the expert had simply avoided these studies and based his opinion on his own clinical experience in diagnosing the spread of cancer cells, then this opinion very well may have been admissible as pure opinion and not subject to a Frye analysis. (4) In other words, if an expert totally ignores scientific literature and bases his or her opinion solely on what he or she believes to be the case as a result of intuition, that is harder for an opposing lawyer to challenge than an opinion based on an analysis of literature.
The Tursi case provides an excellent example of this problem. In Florida Power and Light v. Tursi, 729 So. 2d 995 (Fla. 4th DCA 1999), the Fourth District held that an ophthalmologist could opine as to whether a patient's cataracts were caused by exposure to polychlorinated biphenyls (PCBs) even though there was absolutely no scientific literature that...
