Kumho for Clinicians in the Courtroom
Inconsistency in the Trial Courts
By Harold J. Bursztajn, Milo Fox Pulde, Darlyn Pirakitikulr and Michael
Harold J. Bursztajn, MD, a member of this newsletter's
Board of Editors, is co-director of the program in psychiatry and the
law at Harvard Medical School. Milo Fox Pulde, MD, practices
internal medicine at Brigham and Women's Hospital in Chestnut Hill, MA. Darlyn
Prakitikulr is a premedical graduate of Princeton University. Michael
L. Perlin is a professor of law at New York Law School. The
authors would like to thank Thomas G. Gutheil and Robert
M. Hamm for their helpful editorial comments.
Two Supreme Court rulings, Daubert
v. Merrill Dow Pharmaceuticals Inc., 509 U.S. 579
(1993) and Kumho Tire
v. Carmichael, 526 U.S. 137 (1999), have had a profound
effect on the treatment of expert testimony in the courts. In
1993, the Supreme Court, in Daubert, articulated
guidelines for admissibility of scientific expertise as testimony.
Later, in 1999, in Kumho, the Court focused on the
admissibility of clinical expertise as testimony.
More recently there has been increasing recognition of the inconsistency
of trial courts in their construction and articulation of evidentiary
standards to medical testimony. One proposed remedy is that "Physicians
should respond by correcting courts' misinterpretations of medical practice
and assisting in the development of legal standards that encourage thoughtful
and informed consideration of medical testimony by judges and juries." Kassirer
JP, Cecil JS: Inconsistency in Evidentiary Standards for Medical Testimony:
Disorder in the Courts. 288 JAMA 1382, Sept. 2002.
However, in actual practice, the integrity of a clinical expert's testimony
does not depend on the clinician alone. Rather, both the understanding
of the retaining attorney as to what is needed to formulate an objective
expert opinion, as well as the clinician's dedication to doing so, are
essential. Therefore, it is important to improve communication between
testifying clinical experts and the attorneys who retained them in the
service of providing the finders-of-fact with the most valid and reliable
Daubert and Kumho: What the Cases Held
In 1993, Daubert changed the medico-legal landscape. The ruling, binding
on federal courts and also used as a guideline by many state courts,
allowed jurors to hear evidence and weigh facts from experts whose testimony
included novel scientific theories, if the case warranted — even if those
theories had not gained "general acceptance"
in the scientific community — as long as the testimony was "relevant" and "reliable." Daubert established
that the test for expert testimony admissibility would be whether it
followed the rules of the scientific method. Before Daubert,
the Frye test, enunciated in Frye v. U.S.,
293 Fed.1013 ( D.C. Cir. 1923), had been the norm. Frye allowed judges
to exclude evidence from expert witnesses if it had not been "generally
In 1975, the Federal Rules of Evidence were enacted. FRE 702 represented
a direct challenge to Frye by stating that expert testimony would be
admissible as long as it assisted whoever was responsible for determining
the facts of a case — usually a jury. The testimony no longer had to
meet the "general acceptance"
standard. However, defense-oriented critics asserted that Rule 702 allowed
experts to present shoddy or "junk science" to juries in support
of plaintiff injury claims.
Daubert was decided at a time when "novel" no
longer meant "suspect,"
and the Supreme Court specified in Daubert that the following
five factors should be considered in assessing the reliability of scientific
testimony: 1) whether the expert's hypothesis has been tested; 2) whether
there has been peer review and publication of the methodology; 3) the
frequency of erroneous results; 4) standards controlling the technique's
operations; and 5) acceptance of the methodology in the scientific community.
Under Daubert, judges were assigned a "gatekeeper" role
to determine whether the expert's methodology was sound. In civil cases,
post-Daubert courts are more likely to exclude challenged
expert evidence than they had been before under the Frye standard.
Dixon and Gill (2001) found that challenged expert evidence was excluded
about 50% of the time pre- Daubert. Saks M, Faigman D: Expert
Evidence After Daubert. 1 Ann Rev Law and Social Science 105,
(2005). That figure rose to as much as 70% in years post- Daubert.
Dixon L, Gill B: Changes in the Standards for Admitting Expert Evidence
in Federal Civil Cases Since the Daubert Decision (2001). Daubert's requirements,
when implemented, have thus had profound implications for both medical
experts and lawyers.
Though Daubert signaled the intent of the court to establish
explicit scientifically based rules of admissibility and hold the testimony
of medical experts to a higher standard, the reality of the practical
application of these rules suggests that we have not come far from the
comments of Judge Hand in 1901:
"No one will deny that the law should in some way effectively use
expert knowledge wherever it will aid in settling disputes. The only
question is as to how it can do so best." Learned Hand, Historical
and Practical Considerations Regarding Expert Testimony. 15 Harv.
L. Rev. 40 (1901).
It took the Kumho ruling to extend Daubert from
scientific to clinical expert opinion formulation and testimony:
"The objective of [the Daubert gatekeeping] requirement
is to ensure the reliability and relevancy of expert testimony. It is
to make certain that an expert, whether basing testimony upon professional
studies or personal experience, [should employ] in the courtroom the
same level of intellectual rigor that characterizes the practice of an
expert in the relevant field."
Kumho did more than simply restate the holding of Daubert.
It held that the Daubert "gatekeeping"
obligation applies to both testimony based on "scientific" knowledge,
as well as that based on "technical" and
"other specialized" knowledge. In making the gatekeeping determination,
the trial court "may" consider one or more of the five specific Daubert factors
if it will help ascertain whether the testimony is "reliable."
Overall, Kumho found that the test for reliability is flexible
"Daubert's list of specific factors neither necessarily
nor exclusively applies to all experts in every case … Rather the law
grants a district court the same broad latitude when it decides how to
determine reliability as it enjoys in respect of its ultimate reliability
Commentary on Kumho has been mixed. While some have applauded Kumho for
admitting certain expert evidence rather than simply banishing it as
non-science; others have also raised concerns about the role of judges,
and how Kumho may in effect be replacing the word of experts
with the word of judges: "Together, Daubert and Kumho
Tire do a remarkably clear job of commanding judges to properly
scrutinize fields, presumably including the forensic identification sciences,
before admitting opinions from those fields' practitioners. But one can
never underestimate the ingenuity of judges in finding ways to evade
rules that tell them to do something that would lead to a result contrary
to the one suggested by their intuitions.” Saks MJ: Banishing Ipse
Dixit: The Impact of Kumho Tire on Forensic Identification
Science. 57 Wash. & Lee L. Rev. 880, 880 (2000).
Others have been less receptive to Kumho. One observer,
by way of example, saw Kumho as an effective undoing of Daubert: "[T]he Daubert factors
may or may not be relevant to the reliability of the proffered expert
testimony. The problem, though, is that Kumho leaves judges
with almost no guidance about how to determine whether such testimony
Haack S: Defending Science Within Reason. 254 (2003). However, it should
be noted that Kumho does emphasize the need for corrigibility
— or correctibility — rather than a simple "it is because I say
In its emphasis on making transparent and thus corrigible the process
by which existing data is connected to offered opinion, Kumho is
well in tune with current clinical practice standards. Medical experts
now practice in a climate in which the previously private world of doctor
and patient has come alive with the sounds of doctors justifying their
decisions to a variety of third parties as well as with increasingly
informed and mistrustful patients. The Internet information explosion,
reduction of time with patients and the need to justify decision- making
to nonclinical third parties have placed greater emphasis on patient
education and the corrigibility of clinician reasoning. However, it is
important to note that, while physicians should make use of the current
best available external evidence about medical care (as the practice
of evidence based medicine calls for), such physicians also need to be
wary of turning this practice into a substitute for actually assessing
the primary literature and understanding its validity. Physicians need
to be able to change their minds, to update, revise, and discover and
then justify their opinions as new reasons are offered, data introduced
and analyses completed. In effect, clinicians now often practice in a
consultative mode where transparency of clinical judgment and accountability
under conditions of clinical uncertainty are the rule. Without this transparency,
mistrust and suspicion would pervade the doctor- patient relationship,
for what is not transparent is too often assumed to be biased or corrupt.
Thus, it is important for physicians to be able to articulate the basis
of their clinical reasoning to patients, colleagues, and third parties.
No longer can clinicians simply be silent, or when a clinical opinion
is challenged, simply respond with an "it is because I say so" paternalism.
Guidelines for Clinicians
What then can a medical professional and the retaining attorney do to
make sure that expert testimony will be considered admissible by the
trial judge? There is no question that the cases we've discussed may
confuse clinicians. In an effort to ameliorate some of this potential
confusion, we suggest the following guidelines be used in cases that
raise Daubert/Kumho issues:
It is imperative that experts follow the highest standards of their profession
while preparing to testify and when testifying. Experts must be objective,
independent, and preserve their integrity in an adversarial process.
They must avoid conflicts of interest and testify accurately and appropriately.
This is critical if expert testimony is to be regarded as reliable.
If Daubert/Kumho demands that the expert's
testimony represent both the clinical evidence and medical facts, then
the expert must have credible experience in the practice of medicine,
knowledge and familiarity with the legal process and standards, and the
ability to offer a valid translation of clinical decision-making fundamentals
into a meaningful forensic opinion. An active clinical and consulting
practice, teaching experience and an in-depth understanding of the relevant
facts, analyses, methods and controversies is important. Being able to
update the nature and degree of certainty of one's clinical formulation
is also a critical attribute for the expert who successfully fulfills
the post- Daubert/Kumho standards.
The practice of evidence-based medicine and thrust of Daubert are
the same — the methods used to reach a conclusion must be scientifically
accurate, valid and applicable to the case at hand. Experts and their
retaining attorneys need to realize that the new federal and state court
mandates demand their opinions have strong foundation, and may only be
admissible if the opinions follow the methodological rules of clinical
decision-making under conditions of uncertainty, and are reliable and
relevant. Experts need to understand the principles of clinical evidence
and clinical reasoning, apply them to each case and incorporate them
in their opinion formulation. For example, substitute the word "case"
for "patient" or "patient's illness" and the practice
recommendation quoted here sounds remarkably like the Daubert court's
recommendations for expert testimony and can be applied in other situations: "Does
this diagnostic hypothesis adequately explain all the patient's clinical
findings? Is this hypothesis pathophysiologically coherent? Does this
diagnostic hypothesis provide the best fit to the pattern of the patient's
illness? Is there no hypothesis that is simpler? Is this diagnostic hypothesis
robust to attempts to falsify it? Does this diagnostic hypothesis best
predict the subsequent course of the patient's illness?" Kassirer
JP, Kopelman RI: Learning Clinical Reasoning. 32 (1991).
Expert witnesses must understand that they function as teachers and educators,
and the effective performance of their role demands a unique combination
of oral and written communication skills and the ability to relate to
many different audiences. The expert needs to maintain objectivity, yet
must also maintain ongoing dialogue with the retaining attorney and experts
from other disciplines so as not to
"lose sight of the forest for the trees."
Experts must be able to articulate a clear, concise, coherent, and compelling
narrative with respect, authenticity and sincerity to the triers of fact
of the case. This means paying attention to both the stated content of
the testimony and the manner in which it is offered. Content is most
effectively communicated through an in-depth knowledge. The expert must
conduct a thorough review and analysis of the data and be familiar with
the totality of the facts, conflict as to facts, and the literature,
and be meticulous in detail, organization, and reasoning. Effective experts
understand that testimony is an ongoing educational workshop with the
judge and the jury. Experts who communicate and collaborate with attorneys
can ensure that on direct questioning the attorney asks the fundamental
questions that permit them to simply yet deeply present their analyses.
Furthermore, the expert must be able to carefully analyze and anticipate
how any direct examination testimony can be distorted on cross. In a
consultative role experts can also provide insights that enable the attorney
to more effectively cross-examine opposing witnesses.
Respect the Intangible
... Yet make it tangible. As when consulting to a fellow clinician, experts
have to pass the "dinner companion"
test or the truth of their opinions will not resonate with the jury or
influence the outcome. In other words, the expert must be able to make
clear to the layman that his testimony is reliable and can be trusted.
On one hand, testifying experts need to exhibit sufficient commitment
to their opinions to meet the level of medical or clinical certainty
expected from one clinician consulting to another. On the other hand,
clinical commitment and medical certainty are not satisfied by unsupported
statements from the expert. The validity, reliability and relevance of
the expert's method need to be illustrated in a meaningful manner. The
expert's report is the most tangible evidence of the expert's methods.
"Heuristics" is a cognitive psychology construct that refers
to the implicit rules of thumb of reasoning that individuals use to oversimplify
complex information-processing tasks. On one hand, the use of these heuristic
devices may be helpful in making complex decisions in real time. Garb
H: Clinical Judgment and Decision Making. 1 Ann. Rev. Clin. Psychol 67
(Apr. 2005). However, used out of context, heuristics can cause decision-
makers to ignore or misuse items of rationally useful information, leading
to distorted and systematically erroneous decisions. For example, as
a result of the over-reliance on the
"vividness" heuristic, one single, vivid, memorable case can
swamp a mountain of abstract, colorless, yet relevant data. Heuristics
also have implications for the different ways in which judges and juries
approach the decision-making process, particularly given the fact that
judges are more likely to follow precedent while juries are more likely
to follow group decision- making patterns. A major pitfall in group decision-making
is the vulnerability to a risky shift to vivid examples. If ordinary
people's judgments are distorted by cognitive biases, then experts prepared
with staggering statistics or other striking examples have the capacity
to take advantage of the vividness heuristic and influence the jurors'
Judges are also vulnerable to the use of heuristics. In particular, an
individual judge may be especially susceptible to the "anchoring
and adjustment" and conservatism heuristics. The "anchoring
heuristic is characterized by the decision- maker coming to a provisional
judgment on the basis of the testimony heard first, and then adjusting
his or her opinion on the basis of later testimony. The result is that
the earlier testimony remains dominant and pervades the decision-maker's
entire decision-making process. Related to the anchoring heuristic is
the conservatism heuristic. In anchoring, a decision- maker is influenced
by earlier examples, and anchoring does not typically occur when the
interval between these examples is long and filled with other judgments
or items. In conservatism, on the other hand, the decision maker will
continually be influenced by an opinion he believes he held earlier,
even though he may or may not have. In many areas of the law, research
reveals that the use of such heuristic devices
"permeates both the trial and the appellate processes." Perlin
ML: Pretexts and Mental Disability Law: The Case of Competency. 47 Univ.
of Miami L. Rev. 625, 659 (2003).
It is essential that expert witnesses insulate themselves from the "pernicious"
use of such heuristics in their testimony. Perlin ML: There's No Success
Like Failure and Failure's No Success At All: Exposing the Pretextuality
of Kansas v. Hendricks. 92 Northwestern Univ.
L. Rev. 1247 (1998). Being cognizant of the presence of heuristic
devices, and how they are used can be extremely important in challenging
the methodology of opinion formulation of a clinician expert.
While these guidelines are imperfect at best, they are aimed at mitigating
some of the confusion faced by clinicians retained as experts in the
post-Kumho era. The clinical expert faces many challenges,
and must balance the need to demonstrate their validity as scientists
with the need to be able to communicate with laypersons in a cogent manner.
These guidelines serve as an attempt to help in this endeavor.
Kumho has had a tremendous impact on the role of the testifying
clinical expert in helping the finder of fact's pursuit of justice. In
the post- Daubert/Kumho world, there are more
incentives to identify and use qualified clinical experts and to collaborate
with them; Daubert/Kumho challenges to exclude
or limit expert testimony, the increased complexity of clinical decision-making
and information and the growing sophistication of judges and jurors secondary
to the dissemination of knowledge by the media and Internet, all contribute
to the need for guidelines distinguishing between acceptable and unacceptable
Although alternatives to the current system have been suggested, few
seem feasible to apply. It has been recommended that, in complex cases,
judges use their own "experts" or expert panels to assist in
deliberations. Walker L, Monahan J: Scientific Authority: The Breast
Implant L itigation and Beyond. 86 Virginia L. Rev. 801
(2000). There is no guarantee, however, that courtappointed experts will
be free from bias. Although the challenges for the judicial system in
evaluating complex technical and scientific issues are formidable, court-appointed
experts "pose risks, due primarily to outmoded confidence in the
certainty of science and assumption about the neutrality of experts who
are free of party allegiances."
Deason RE: Court-Appointed Expert Witnesses: Scientific Positivism Meets
Bias and Deference. 77 Oregon L. Rev. 59 (1998). Critics
have pointed out that the use of designated panels of experts or specialized
courts undermines the "checking function of the adversary system." Moreover
court appointment tends to confer upon court-appointed experts, some
of whom may have subtle yet substantial conflicts of interest that even
they themselves may not be aware of, the halo of judicial infallibility.
By the same token, the blind use of clinical guidelines as a gold standard
has to be avoided in light of the emerging data as to conflicts of interest
due to potential vested interests of guideline authors or their being
funded by third parties (managed care organizations, pharmaceutical companies)
which may have a stake in the process and content of formulation of such
guidelines. Taylor R, Giles, J: Cash Interests Taint Drug Advice. 437 Nature 1070
Experiments have been performed to ascertain the conditions under which
judges accept expert advice. In a study by Swol and Sniezek (Van Swol
LM, Sniezek JA: Factors Affecting the Acceptance of Expert Advice. 44 Br
J Soc Psychol 443 (Sept. 2005)), two experiments were performed
to determine factors that could increase the utilization of expert advice.
In the first experiment, five factors were examined: 1) the judge's trust
in the adviser; 2) adviser confidence; 3) adviser accuracy; 4) the judge's
prior relationship with the adviser; and 5) the judge's power to set
payment to the adviser. In the second experiment, trust was examined
without the role assignment to judge or adviser. The study found that
expressions of high confidence by the advisers increase the acceptance
of advice, and that even when participants communicated freely, face-to-face,
written expressions of confidence were the best predictors of advice
As for evidence, it is also worth noting that there has been a split
in the federal appellate circuits in the construction of Daubert in
subsequent cases. For example, regarding social framework evidence, while
the Third Circuit in Heller v. Shaw Indus., 167 F. 3d 146
(3d Cir. 1999) adopted a relatively open approach and has allowed a good
deal of clinical judgment to support the opinion, the Fifth Circuit in Black
v. Food Lion Inc., 171 F.3d 308 (5th Cir. 1999) took a more strict
approach, and only allows opinion on medical causation that is supported
by considerable research.
While Daubert has had a profound effect on clinical experts
and lawyers, some plaintiffs' attorneys and their advocates have claimed Daubert to
be unnecessarily burdensome, and have even gone as far as to say that Daubert has
had a substantial negative effect on the plaintiff, noting that it adds
substantially to the quantum of evidence that a plaintiff must introduce,
and to the power of the judge to affect the outcome of the trial. Lakoff
G: A Cognitive Scientist Looks at Daubert. 95 Am J Public Health 114
(2005). On the other hand some defense-oriented commentaries decried
the persistence of Frye in a variety of state courts. Bernstein
D: Quackspertise. The Wall Street Journal, Sept. 30, 2006,
Variability of rule and interpretation aside, attorneys and judges who
possess some of the same attributes that are indicative of clinical expertise
are also in the best position to do justice. These include being open
to learning new facts, making well founded inferences, and a renewed
commitment to open and candid communication and collaboration.
As the complexity of cases increases it is even more critical that attorneys
provide the clinical expert with a complete database of discoverable
information with a realistic timetable so the expert can review and analyze
both the medical facts and relevant literature in order to develop an
opinion that is transparent and corrigible. Clinical experts need to
be prepared to engage in a transparent and corrigible opinion formulation
process focused on achieving the requisite degree of medical or clinical
certainty (most often, more likely than not) rather than to simply offer
opinions. Attorneys must eschew clinical experts whose testimonies are
based on such opinions. Clinical experts also need to anticipate how
their testimony can be distorted on crossexamination and be prepared
to address such distortions. In this new post-Daubert/Kumho environment
attorneys and judges will find most helpful those experts who are able
to articulate not merely their opinion but the process by which they
employed their expertise in data review and analysis and methods of inference
to formulate their opinion to the requisite degree of professional certainty
required by the finder of fact.
By making clear in a report the reasoning and analysis which is at the
heart of an opinion formulation, the twin goals of allowing for earlier
dispute resolution and for preparation of testimony which can withstand Daubert-
or Frye- based challenges if the case goes to trail can
each be achieved.