Deliver a Daubert-proof expert report: defense challenges to plaintiff expert testimony have become a routine part of civil litigation. Here's how to combat them with a thorough, well-documented report.

From the moment you retain an expert, you must understand that "the day of the expert who merely opines and does so on the basis of vague notions of experience is over." (1) According to For the Defense, published by the Defense Research Institute, a challenge to the admissibility of expert evidence--based oil Daubert v. Merrell Dow Pharmaceuticals Inc. (2)--"is a potent weapon of growing importance to the corporate defendant's arsenal in civil litigation" and a "standard part of the development of the defense." (3)

To meet such a challenge, you must work closely with your scientific experts to prepare a thorough, well-documented report that will meet Daubert's admissibility criteria.

Your expert's report should be written like a master's thesis. Citations to reference materials are critical. Footnotes and references must support the expert's assertions. The expert's credentials and methodology should also be explained.

The expert's qualifications. The report must include a detailed recital of the expert's qualifications. Do not assume that the court will read the expert's resume and understand wily he or she is qualified to testify. Have the expert include details about relevant experience outside litigation to show how his or her opinions were formed by experience in the field, not by for-hire litigation work. Make sure the expert stresses relevant research that was paid for by independent entities. The expert's research grants or appointments to government or scientific panels help dispel the notion that he or she is outside the mainstream or a "hired gun." A detailed narrative of professional achievements will show the court that many knowledgeable people and reputable organizations have considered your expert credible.

Ideally, your expert will have published peer-reviewed research in the area; the report should explain the relevance of these articles to the court. Remember that there is more than one kind of peer review. For example, presentations the expert has given at professional conferences or academic department meetings have undergone a form of peer review and should be included in the report. If your expert has discussed his or her opinion with peers who concur, that information should be included.

The expert should also explain in the report the relevance of memberships in specific professional organizations, especially those that require the completion of specific research--not merely the payment of dues--to qualify for admission.

Materials and methods. In the scientific world, papers open with a "materials and methods" section, so your expert's report should have one, too. Otherwise, the expert is not applying the same care that he or she would use in nonlitigation work.

In this section, the expert should describe the methodology and reasoning processes generally used in the relevant field, with citations to the appropriate authorities that confirm his or her opinions.

For example, an expert giving an opinion about the cause of a fire would say the investigation was conducted according to National Fire Protection Association (NFPA) Standard 921. (4) An epidemiologist should quote Bradford Hill, who set out factors for evaluating the correlation between exposure and diseased A physician might describe the method taught in medical school for using medical history and physical examination to assess a patient. These types of materials are called "methodology literature."

This section of the report should also include a list of the materials the expert reviewed. Make sure that he or she considers both supporting and dissenting literature.

The report should explain the links among the expert's qualifications and expertise, the materials and methods used, and the proposition that he or she is advancing. The report should include references to:

* the expert's articles published in peer-reviewed journals that support his or her approach in evaluating the case

* reports prepared by private entities or government agencies that use a similar analysis

* other peer-reviewed reports that used the same methodology the expert is using in the case.

Encourage the expert to use phrases that emphasize the reliability of his or her methods. For example:

* "The method is not novel; this approach has routinely been used outside litigation in...."

* "I used this methodology in writing articles for the following peer-reviewed publications...."

* "If I were working for the defendant, I would use this method."

* "The defendant and the defendant's experts have used the same methodology in the ordinary course of their business and in published literature, and they have drawn conclusions pursuant to these methods."

* "Past opinions using this method have been allowed by courts in the following cases...."

* "This method is discussed and accepted in the Federal Judicial Center's Reference Manual on Scientific Evidence."

* "This methodology has been used in my field since ... [citing appropriate methodology literature]."

Keep in mind that in some fields, such as accident reconstruction, results are never published. If the expert is in such a field, he or she should say, "This type of work is not normally peer-reviewed or published."

Applicable standards. In some fields, investigations and reports must meet certain standards. You and your expert must be aware of them and he sure the expert's report complies; doing so call give you an edge and strengthen the expert's credibility. For example, a report that states it was written in compliance with Standard Practice for Reporting Opinions of Technical Experts (ASTM E620-97)--promulgated by ASTM International, a nonprofit organization that develops voluntary standards--has an advantage, since the methodology is set forth in the standard and is recognized as acceptable in the field.

NFPA 921, Guide for Fire and Explosion Investigations, is another example. This publication's purpose "is to provide guidance to investigators that is based on accepted scientific principle or scientific research." (6) According to the guide, "A fire investigation conducted by using the scientific method [in NFPA 921] should be admissible under Daubert." (7) Fire cause and-origin experts who were unaware of this standard have been excluded from trial. (8)

Making connections

As Daubert jurisprudence evolves, it becomes clearer that "gaps" in the expert's chain of inference can be fatal. Make sure the expert explains the links between points; the expert will be excluded if he or she offers an opinion without an adequate factual or methodological foundation. Propositions should be explained and substantiated with empirical evidence. The report should cite authoritative literature, treatises, and industry or government reports and standards supporting the expert's opinion. If your expert extrapolates causation from animal studies, he or she must sufficiently explain why the animal studies support that conclusion.

Any expert on causation should testify that he or she has "ruled in" the substantial cause and "ruled out" other possible causes. The report should include phrases like: "I have ruled in X as a cause, for the following reasons"; "I have ruled out these other potential causes, for the following reasons"; and "I have considered the following causes and utilized a differential methodology in arriving at my opinion."

This method of identifying disease causation has become widely accepted in medicine and in the courts. Doctors use "differential diagnosis" to consider all possible causes of a patient's condition and rule out those that don't fit the case. According to Harrison's Principles of Internal Medicine:

   The clinical method always proceeds in a
   series of logical steps. The perceptive student
   will hole certain similarities between
   the clinical method and the scientific
   method. Each begins with observational
   data which suggest a series of hypotheses.
   The latter are tested in the light of further
   observations, some of which are made in
   the clinic and others in the laboratory.
   Finally, a conclusion is reached, which in science
   is called a theory and in medicine a
   working diagnosis. (9)

A diagnosis is based on "the recording of the patient's symptoms and signs, the consideration of the various disorders that can give rise to them, and the effective utilization of measures which will support and confirm or alter the first impressions and ultimately lead to a firm diagnosis." (10)

Harrison's describes the methodology physicians are taught in medical school and use every day. Have your medical expert use these citations as methodology literature in the report.

Before you talk with your client's treating physician, read Turner v. Iowa Fire Equipment Co., which approved "differential diagnosis" as an appropriate scientific method for use in litigation. (11) The decision is instructive because the court excluded the plaintiff's treating physician for a number of reasons. The physician used a differential diagnosis to identify the plaintiff's condition but not its cause. He made no attempt to consider all possible causes or to exclude each potential cause until only one remained. The physician did riot evaluate which of two or more nonexcludable causes was more likely to have caused the condition, and he failed to consider scientific literature suggesting a causal link between other exposures and the plaintiff's disease.

Make sure your expert avoids these mistakes.

Challenging the defense report

Remember, Daubert applies to every expert--not just those testifying for plaintiffs. If the science is on your side, tell the court you may bring a Daubert challenge.

Go on the offensive at the defense expert's deposition. Ask your opponent's expert to identify pre-litigation experience, publications, and speeches that relate to the subject. Ask the witness to explain his or her methodology if the expert failed to do so in the report. Some experts will not be able to explain their methods--which is grounds for excluding their opinions. If the defense expert's report does not have a methodology section, get one of his or her published papers and use it as a deposition exhibit to show that the expert conducts litigation work differently, and less carefully, than his or her scientific work.

Use your expert to demonstrate how the opponent's expert has departed from the standards of the profession. Have your expert explain by affidavit how a test could be performed to verify or refute the defendant's hypothesis. Use a second "methodology" expert to comment on your opponent's inappropriate methodology. Compare your excellent expert report with the defendant's woefully inadequate one.

Preparing a strong expert report reduces the chance that the defense will launch a successful Daubert challenge and helps you and your expert focus on the most important issues in the case. With these issues in mind, you can launch an expert challenge of your own, or defeat a challenge even in a court that does not follow Daubert.

Notes

(1.) Kemp v. Tyson Seafood Group, Inc., No. 2000 WL 1062105, at *7 (D. Minn. July 19, 2000).

(2.) 509 U.S. 579 (1993).

(3.) Donald R. Frederico et al., Owning Daubert: Challenging Expert Testimony as a Defense Strategy, FOR THE DEFENSE, Nov. 2000.

(4.) NAT'L FIRE PROTECTION ASS' N, NFPA 921: GUIDE FOR FIRE AND EXPLOSION INVESTIGATIONS (2001) [hereinafter NFPA].

(5.) Bradford Hill, Environment and Disease: Association or Causations?, 58 PROC. OF THE. ROYAL SOC'Y OF MED. (1965).

(6.) NFPA, supra note 4, at 921-1.

(7.) Id. at 921-111-11.

(8.) See Am. Family Ins. Group. v. JVC Americas Corp., 2001 WI. 1618454, at *3-4 (D. Minn. Apr. 30, 2001).

(9.) HARRISON'S PRINCIPLES Of INTERNAL MEDICINE 4-5 (G. Thorn et al. eds., 8th ed. 1977).

(10.) Id. at XXIX.

(11.) 229 F.3d 1202 (8th Cir. 2000); see also Westberry v Gislaved Gummi AB, 78 F.3d 257, 262-63 (4th Cir. 1999) (collecting casts approving rise of differential diagnosis).

MARTHA K. WIVELL is an attorney with Robins Kaplan Miller & Ciresi in Minneapolis.