Where many medical malpractice cases often turn into a "battle of the experts," it is rarely enough that a witness meet just the basic statutory and evidentiary rule requirements, as the effectiveness of any medical expert is also directly impacted by his or her credibility, likability, persuasiveness, and other subjective qualities. An expert must be qualified, but also credible to a judge and the jury.
Idaho Code Section 6-1012 requires that a plaintiff must, "as an essential part of his or her case in chief, affirmatively prove by direct expert testimony and by a preponderance of all the competent evidence, that such defendant . . . negligently failed to meet the applicable standard of health care practice of the community in which such care allegedly was or should have been provided, as such standard existed at the time and place of the alleged negligence of such physician and surgeon, hospital or other such health care provider and as such standard then and there existed with respect to the class of health care provider that such defendant then and there belonged to and in which capacity he, she or it was functioning . . ." Further, Idaho Rule of Evidence 702 stipulates that a witness "qualified as an expert by knowledge, skill, experience, training, or education may testify in the form of an opinion or otherwise if the expert's scientific, technical, or other specialized knowledge will help the trier of fact to understand the evidence or to determine a fact in issue."
On the path to trial, it is often the case where the plaintiff's expert testifies the standard of care was not met, the defendant's expert testifies it was, and each expert explains his or her respective qualifications, background and experience to add credence to the proffered opinions. In these scenarios, the outcome of the case becomes highly impacted by the jury's perception of the experts. Therefore, it is important to select a qualified medical expert who not only carries sufficient academic credentials, experience, and training, but also presents effectively, credibly and persuasively. It is equally important for defense attorneys to assess an expert witnesses's subjective qualities well in advance of trial.
Factors Influencing Perception of an Expert Witness
Subject Matter and Case Knowledge
As a threshold matter, as the proponent of the expert witness, attorneys should find an expert with relevant knowledge and experience to speak with authority to the case's issues. The attorney must be prepared to articulate the expert's credentials, education, board-certifications, specialty(ies), publications, presentations, and other experience to establish the expert's qualifications and credibility. When first receiving the expert's CV, it is helpful to read it once for content, and a second time while considering how a judge and a jury would view this expert's credibility. The other component is also ensuring that the expert knows the case. It is not uncommon for experts to be retained on multiple cases at a time, so ensuring that your expert studies the case facts, records, and materials is paramount. Even if an expert is a renowned authority in their field, if they have not studied the medical records, deposition transcript(s), and other case documents, it is far to easy to fall into giving testimony adverse to the defense. Further, demonstrating a lack of knowledge of the facts of the case undercuts the expert's credibility in the eyes of the jury and judge. If an expert appears completely unfamiliar with the case, it is possible that a judge may strike that expert's testimony from the record, or preclude further testimony from that expert, which significantly and detrimentally impacts the defense's position.
Also important is to evaluate sources of bias that an expert may harbor, or that may be perceived by a judge or jury. Sources of such perceived bias could be prior retention of that expert, an expert's categorical rule to only provide expert testimony for the defense, or pre-existing personal relationships with the parties/attorneys. Percipient jurors may view any of these as evidence that a witness if biased in favor of the defendant(s) and accordingly discount the testimony. Similarly, when there is an appearance of bias, loss of credibility typically follows. Further, if there is reason to support a determination that an expert was inappropriately swayed by the evidence, injury, parties, and/or attorneys, that can suffice as reason to disqualify the witness's testimony.
Demeanor and Etiquette
While it would seem axiomatic that an expert witness would know how to behave professionally and courteously, and dress appropriately, it would be a misstep to automatically assume these things.
Attorneys should anticipate engaging in preparation sessions with experts, which include advising the expert that when they present to provide testimony, he/she should be clean, well-groomed and conservatively/professionally dressed; scrubs should be changed out of, shirts should be collared and pressed, skirts should be at appropriate lengths. With respect to the expert's habits and communication style, attorneys would be remiss not to remind experts to appear respectful, calm, confident, and collected; that the courtroom (or deposition room) is not the place for laughter, slang terms, uncontrolled laughter, emotional outbursts, or chewing gum. During depositions that are videotaped, it is often helpful to advise the expert to not take a glass of water into the camera frame, due to natural tendencies to reach for it at sporadic times of nervousness. Of course, attorneys should present this advice in conjunction with explaining that the judge and jury will be evaluating the expert on body language, dress, and etiquette. Interestingly, the impact of an expert's likability on the credibility of the expert varies among personalities: extroverted jurors tend to view witnesses they like as more credible, while introverted jurors' perception of credibility was not impacted by whether or not they like the expert.
Prior Testimony and/or Claims Against the Expert
Particularly relevant in medical malpractice cases where the proffered expert is also a practicing physician, is any prior deposition and/or trial testimony rendered by the expert, and any prior claims made against the physician. Prior deposition and/or trial testimony should be obtained and reviewed with an eye toward identifying similar areas of testimony given in the past. For example, if a defense expert was previously retained by a plaintiff and provided testimony that surgical treatment is always necessary in X situation, but plans to opine for this defense that surgical treatment was not necessary nor within the applicable standard of care in a similar situation, a case of diminished credibility may arise with using this expert. Further, it is important to inquire about past claims or lawsuits made against the expert: for example, revealing that an expert has had 7 prior lawsuits during his career that resulted in 5 plaintiff's verdicts and $4.2 million dollars of damages, collectively, has a high likelihood of undercutting the expert's credibility and effectiveness in the eyes of the jury.
Facts, and Just the Facts
While each state's rules of evidence may slightly vary, most are similar to or echo Federal Rule of Evidence 704(a), which instructs that expert witnesses may offer testimony on factual issues that a jury will decide as the trier of facts. What this means is that it is important that an expert's testimony does not cross into the purview of the judge's considerations and instructions on the law. An expert witness cannot render legal opinions, advise the jury on the law, or state what law applies to the case, as those are issues and determinations reserved for the judge.
By proactively evaluating a prospective expert's background, education, experience, past litigation history, and engaging in candid preparation for giving testimony, attorneys can work to ensure that their expert witnesses are not only qualified but also likely to be perceived by the judge and jury as likable, persuasive, and credible.