It is funny how things work out sometimes. Consider Daubert v. Merrell Dow, the well-known U.S. Supreme Court case dealing with the admissibility of expert testimony. This decision purports to make it easier for litigants to introduce opinion testimony, but ironically it has had the opposite effect. That circumstance is something that impacts all litigation, including medical malpractice cases.
As most of you know, in Daubert the plaintiff proffered an expert who was prepared to testify that the drug Bendectin caused certain birth defects in the children of pregnant women who ingested the anti-nausea drug. The specific issue was whether the expert testimony was sufficiently reliable to be admitted under Federal Rule of Evidence 702. At the time, the controlling common law rule established in Frye v. United States, was that such testimony was admissible only if it was "generally accepted" in the relevant scientific community. Daubert, however, refused to apply Frye to Rule 702 and instead held that even where opinion testimony is not "generally accepted" it can nevertheless be admissible if it is based on accepted scientific methodology. In short, the Supreme Court said that even those conclusions which are not broadly adopted by one's peers, my nevertheless be worthy of admission if they are the product of sound scientific thought. It is the job of the trial judge, said the high court, to serve as the "gatekeeper" and determine whether the challenged testimony passes muster under that standard.
On its face, Daubert would seem to make it easier for parties to introduce expert testimony since it liberalizes the standard (or "lowers the bar") of admissibility, but in reality, it has made it harder to introduce such testimony. How so?
First, Daubert has heightened lawyers' awareness of potential challenges to opinion testimony, as a result of which the sheer volume of motions to exclude such evidence has increased several fold. The notion that expert testimony must meet some threshold standard of reliability --- be it the more rigid "generally accepted" rule of Frye or the more liberal Daubert standard --- has been around for years, yet prior to Daubert there were relatively few reported decisions dealing with pre-trial challenges to expert witnesses. Since the Daubert decision, however, there has been a huge increase in the number of these motions. A plausible explanation for this growth is simply that Daubert has brought the issue to the legal forefront. And, it stands to reason that the more challenges which are filed, the more times experts are going to be prohibited from testifying, i.e. the harder it will be to introduce expert testimony.
In addition to increased visibility, the second factor leading to the disqualification of more experts, at least in state court litigation, is that Pennsylvania does not apply Daubert rules to Daubert hearings. Although Daubert is a federal court decision, the term "Daubert hearing" has been fairly incorporated into the legal lexicon to refer to any pre-trial challenge of the reliability of expert testimony, regardless of whether it arises in federal or state litigation. However, the Pennsylvania appellate courts have not adopted Daubert, but instead they continue to adhere to the older, more strict Frye "generally accepted" standard of admissibility which was adopted some twenty years ago by our supreme court in Commonwealth v. Topa. (Unfortunately, Rule 702 of our new Evidence Code takes no position on the Daubert issue, so the common law cases continue to control.) Thus --- and this is the ultimate irony --- the very case which rejected the Frye rule has caused many more experts to be subject to its stricter standard.
There are some other interesting issues surrounding the Daubert debate, among them the question of whether Pennsylvania should affirmatively adopt Daubert, and also the potential for abusing the Daubert hearing. Those matters may be discussed here in the future, but for now the initial observation on Daubert is the sense of irony surrounding it.