Daubert: Very Convoluted, Usually Confusing to Many, Nevertheless Elegant
Posted by
Armand RossettiAugust 06, 2009 4:32 PMPretrial Daubert hearings are essentially motions in limine that ultimately decide whether an expert is qualified, and whether that expert: 1) has based an opinion on sufficient facts or data; 2) will be able to testify using “reliable principles and methods,” and; 3) has applied the principles and methods reliable to the particular facts of a given case.
The Daubert factors are based Rule 702 of the Federal Rules of Evidence, which is used to examine an expert’s testimony as a whole. In addition under Rule 703, experts may reasonably rely on documents and information that may be inadmissible during trial. It is also Rule 703 that forms the basis for inquiry, concerning the reliability of any data that supports expert testimony. Furthermore, Rule 703 relaxes the requirement that experts need to acquire personal knowledge about the matter to which they testify. Finally, Rule 703 has little to do with whether an expert’s testimony, as a whole, meets Daubert standards. That determination rests with Rule 702.
Since a Rule 702 is more “holistic,” judges acting as gatekeepers should not require each document, or particular source of data that experts might use to form opinions, to be dispositive. In other words, Courts should not be conducting a Daubert inquiry on each and every document and deciding whether or not each document is qualified as being stand-alone reliable.
Instead, Judges should conduct a Rule 702 analysis in light of an expert’s reasoning and methodology in its entirety, or to analogize, judges should decide testimonial reliability under the totality of the medical, scientific and technical circumstances.
Daubert also requires that an expert witness has to assist and not to confuse the Trier of fact. If the Jury (Trier of fact) can understand whether a substance in particular is able to cause an injury and whether an injury resulted from that particular substance, an expert opinion would be redundant and unnecessary.
On the other hand, Rule 403 requires a Court to balance the probative value against the prejudicial effects of expert witness testimony. Courts should not confuse Rule 403 with Rule 703.
For example, experts do not necessarily need an epidemiological study with an internal control group or randomly selected participants to be able to show an association between exposure to a chemical and resulting bodily abnormalities. That is true because an association is not causation. While a case study might not be sufficient to show causation, it may be all that is necessary to show an association between presence of a toxic substance and a resulting injury.
However, if a Court mistakenly uses Rule 403 in place of Rule 703 to disqualify a source of information because that source in itself does not suffice in supporting causation, that Court has prematurely obviated the need to take all of the information, in the aggregate, and to perform a Rule 702 analysis to examine an experts methodology.
It is the expert in the first instance, and not the Court as gatekeeper, who is the judge of what recourses to choose to assist her in forming an opinion. It is the expert who will initially filter out prejudicial information as being irrelevant. The Court then uses Rule 703 to assure the reliability of evidence by vetting the bases that forms an expert’s testimony.
Let's take environmental asbestos infiltration an example, the fact that an air sampling study is an associational (or case) study affecting a few subjects, rather than a higher evidence based epidemiological study that affects several hundred subjects should not bar an expert from using the case study to inform her opinion about the dangers of asbestos release in the environment. The fact that a single case study published in a peer reviewed journal fails to establish causation under a Rule 703 review should go to the weight that the Jury will give such evidence, but it does not mean that an expert cannot eventually rely upon it in part to form an ultimate opinion.
Of course, if a single case study were the only source of evidence, then the Court might be reasonable in immediately performing a Rule 702 analysis to disqualify the entire testimony. However, the fact that an expert has relied upon several case studies to form an opinion, and has not used even one single epidemiological study should not in itself disqualify that expert’s testimony.
Rule 703 also addresses whether a study is of the type usually relied upon by experts in the field. Experts in different fields may rely upon different types of studies that span several different evidence based scientific levels. Certain professions might consider lower levels of scientific evidence as being adequate to enlighten the community about dangers inherennt in certain practices and procedures. In many instances, legal, ethical or moral considerations render higher evidence based, epidemiological studies forever unavailable.
For instance, the profession of orthopedic surgeons (community) may require only a certain number of evidence based medicine (EBM) level IV, peer reviewed case studies, instead of level I epidemiological studies, before that community decides to strongly recommend that surgeons discontinue using a certain procedure. In particular, the community may determine that a medical device, such as a pain pump that employs a medication, such as bupivacaine, is causing shoulder chondrolysis at a much higher than usual incidence. The community then conducts several different types of level IV EBM studies that expose the pump and anesthetic as being too dangerous for continued use in joints between bones. Just because it is unethical to conduct double blind, epidemiological studies, Courts should not consider the entire orthopedic decision making process to be less “scientific” than other such investigations.
If under Rule 703, Courts were to individually disqualify each and every level IV article as being insufficient and/or unreliable to base an association that might in light of additional studies, lead to causation, no orthopedic expert would be able to gather any evidence to form an opinion, and have a Court perform a Rule 702 analysis. That is the primary reason that many document-by-document decisions that have incorrectly occurred under Rule 703 have unfairly usurped the expert’s opportunity to undergo a required Rule 702 review under Daubert. This means that many plaintiffs and perhaps many defendants have not had their day in court. For a more comprehensive discussion, see US v. WR Grace.