Using Daubert to Defeat Causation in the Delayed Diagnosis Claim

Relevant personal experience with a disease process is the equivalent of a case report, which cannot establish a causal link when scrutinized under the rigors of Daubert. A case report is a description of clinical events involving one or a few individuals that is published in a medical journal; “[It] reports unusual or new disease presentations or suspected associations between two diseases, effects of medication, or external causes of diseases.” Reference Manual on Scientific Evidence at 474-75 (Fed. Judicial Ctr. 2d ed. 2004), available at http://air.fjc.gov.. (emphasis added). When the development of a disease is evaluated in a collection of patients with a common experience or exposure, a report on the group in the literature is called a case series. The only real difference between a physician's personal anecdotal experience with a disease process in his or her practice and a case report or case series regarding the same disease process is that the latter is published in a medical journal.

Case Reports and Series

There are no controls or comparison groups in case reports or case series, and case series often lack information about whether the individuals evaluated are typical of the population affected by the disease or condition. See Id. Case reports and case series can at best serve to generate hypotheses; they cannot provide a reliable basis for a conclusion that a particular act or omission causes an injury. See Siharath v. Sandoz Pharms. Corp., 131 F. Supp. 2d 1347, 1361 (N.D. Ga. 2001) (“Case reports are not reliable scientific evidence of causation, because they simply describe reported phenomena without comparison to the rate at which the phenomena occur in the general population or in a defined control group; do not isolate and exclude potentially alternative causes; and do not investigate or explain the mechanism of causation.”) aff'd, 295 F.3d 1194 (11th Cir. 2002). As a result, federal courts have uniformly rejected case reports as a foundation for reliable scientific opinion evidence regarding disease causation. See Haggerty v. Upjohn Co., 950 F. Supp. 1160, 1164 (S.D. Fla. 1996) aff'd, 158 F.3d 588 (11th Cir. 1998); Casey v. Ohio Med. Prods, 877 F. Supp. 1380, 1385 (N.D. Cal. 1995); Jones v. United States, 933 F. Supp. 894, 898 (N.D. Cal. 1996) aff'd, 127 F.3d 1154 (9th Cir. 1997); Muzzey v. Kerr-McGee Chem. Corp., 921 F. Supp. 511, 519 (N.D. Ill. 1996).

In the McDowell case, the plaintiff's experts effectively conceded that simply by chance alone, some patients who develop spinal epidural abscesses will develop permanent neurologic deficits, regardless of the timing of medical intervention. See 392 F.3d at 1299-1302. Thus, isolated case reports of neurologic injury, whether occurring in the plaintiff's experts' clinical practice or reported in the literature, were simply not a reliable foundation from which the experts could opine that a delay in treatment under the circumstances experienced by the plaintiff caused the plaintiff's neurologic injury.

While the disciplines of medicine and law both strive to reliably answer causation questions through the well-reasoned consideration of research and data, the exigencies of patient care may sometimes encourage physicians to forsake the rigorous analysis that is required in the laboratory or the courtroom for simple and intuitive answers to otherwise complex medical questions. As the U.S. District Court for the Northern District of Georgia has artfully stated:

“[D]octors every day seek to determine causes of injury and illness and make patients healthier. In their eternal quest for “the answer,” however, doctors sometimes believe that they have found a cause when they have not necessarily done so. Doctors in their day-to-day practices stumble upon coincidental occurrences and random events and … confuse association and causation. They are programmed by human nature and the rigors and necessities of their clinical practices to conclude that temporal association equals causation, or at least that it provides an adequate proxy in the chaotic and sometimes inconclusive world of medicine. This shortcut aids doctors in their clinical practices because their most important objective day-to-day is to help their patients and 'first, do no harm,' as their Hippocratic oath requires. Consequently, 'they make a leap of faith.'” Siharath, 131 F. Supp 2d at 1372.

Though medical experts instinctively may seek to employ the same methodology in the courtroom as is applied by doctors throughout the world in their clinical practices, clinical impression and differential diagnosis is not a scientific methodology that meets Daubert demands. General medical principles and anecdotal experience are not subjected to the proper intellectual rigors nor founded on peer reviewed or published studies and therefore do not constitute reliable support for expert medical opinions regarding the causation of disease processes or injuries.

A Strategy for Mounting a Daubert Causation Challenge in Delay Cases

The key to excluding causation testimony in a delayed diagnosis case is early and extensive preparation and methodical questioning during the deposition. Daubert cannot be an afterthought. A well-executed and successful Daubert attack has to be carefully choreographed from the start. If you have waited until after the expert's deposition to begin your Daubert strategy, you have already missed your cue. There simply is no substitute for early and extensive preparation.

Because a Daubert attack is part law and part science, defense experts who are already familiar with the medical literature can and should assist in this process. By the time the deposition approaches, the defense lawyer should be armed and ready to discuss virtually any piece of literature that the plaintiff's expert might throw out in support of his or her causation opinion.

From the outset, the defense lawyer should thoroughly research the medical and scientific literature for all case studies, reports, articles and empirical support of any kind relating to the disease process and the factors influencing prognosis or outcome. In many cases, there will not be sufficient peer-reviewed studies examining the differences in outcomes at various time intervals of treatment due to the ethical complications that the necessary withholding of treatment would impose. If the studies are lacking, the practitioner should attempt to establish that the expert's basis for his or her conclusions is limited to personal clinical experience and anecdotal evidence. The expert may even admit that studies that would scientifically prove his or her theory would be “impossible,” “unethical,” or “pointless” because the theory is within the realm of common knowledge, as was the case in McDowell. In any event, there should be a thorough exploration of the expert's own personal experience in diagnosing and treating the condition, including the various characteristics of his or her patient population.

In the alternative, if studies do exist that purportedly support the plaintiff's expert's opinion that a delay caused an injury, then those studies must be distinguished factually or shown to be unreliable due to flaws in the methodology of the studies themselves. For example, where possible you should seek to establish that the supporting literature is merely a collection of reported case studies or a case series. In addition, you should explore the various characteristics of the subject patients in those studies and establish all known factual differences between the study subjects and the plaintiff, with specific attention to any differences in severity and duration of the condition at the critical intervals. If you have done your homework, then you will be more conversant with respect to these studies than even the expert. Moreover, if you can establish that the expert really is not all that familiar with the details, methodology or conclusions of the study, then you will have a persuasive argument for excluding the expert's reliance on the study altogether.

Similarly, it is crucial that the defense lawyer be equally familiar with the language of Daubert and its progeny. It takes more than a passing understanding of the case's holding to use the principles effectively. Too often, busy trial lawyers wait until it is time to draft the brief before they even read and begin to understand the case law, and as a result they miss a wonderful opportunity to commit the expert to those golden terms and phrases such as “leap of faith,” “case reports,” “medical logic” and “presumably accepted” that are sprinkled throughout the case law and which can doom a plaintiff's expert's causation testimony.

Questions to Ask

Finally, once armed with working knowledge of both the medical literature and the language of the legal opinions, a successful Daubert strategy requires detailed and methodical questioning of the expert at the deposition. The expert should be pinned down, if possible, on any difference in prognosis or outcome that diagnosis and treatment at various intervals would make, and the bases for such opinions. As to the bases for the opinions, if the expert will admit that the “earlier the better” theory is so basic, common or axiomatic as to be ordinarily appreciated and understood by laypersons, you may be able to exclude the expert opinion on relevance grounds by showing that it does not aid the trier of fact as a true “expert” opinion. The defense lawyer also should strive to establish the unpredictable nature of the condition's prognosis, regardless of the alleged delay in diagnosis and treatment, and ferret out any speculation as a basis for the theory.

There are a host of “must ask” questions that should come to mind as you prepare your examination, including variations of the following, tailored to the specifics of your case:

• What empirical evidence exists in support of the opinion?
• Has the theory been tested? Can the theory be tested?
• What is the potential error rate in the theory as shown by testing?
• Does the theory have general acceptance in the community?
• What are the studies on which the expert bases his opinion?
• Were the studies merely a retroactive review of case reports versus prospective, randomized, controlled and blinded studies?
• How large was the sampling for the study?
• How old is the study and is it still valid?
• Where is the theory published in the peer-reviewed literature?
• Was the scientific method followed in the study?
• What were the circumstances of the studies?
• Can you distinguish the subjects of these studies from plaintiff's case?
• Did the studies involve patients with different characteristics, different rates of progression, different duration or severity, or different signs or symptoms?
• Did the studies account for delays at relevant intervals? For example, did they measure the difference in outcome after 1 hour, 4 hours, 24 hours, 72 hours, etc?
• Can the expert point to any studies showing incremental worsening of outcome correlated with an incremental passage of time to support the “earlier, the better” theory?
• Is the condition reversible or treatable and if so when is absolute last point of salvageability? How do you know?
• Are there some cases that are not salvageable, reversible, treatable?
• Are there gradations in the level of injury and if so how are they affected by the passage of time?
• Is there a scientific basis for predicting the extent of recovery based on the hour or day that treatment is rendered?
• What other factors are predictive of a good prognosis?
• What was the expected prognosis for this patient? Was this patient's prognosis better than expected? Worse than expected?
• Do ethical considerations of withholding treatment prevent relevant scientific studies on the issue?
• Is the theory based merely on the expert's personal observation of patients, clinical experience, or anecdotal evidence?
• Is the opinion based merely on medical logic or common sense?
• Is it something that is common knowledge or presumed by the general public?

Conclusion

Above all, abandon the notion that Daubert principles are “too academic” to explore at the plaintiff's expert's deposition, and resist the tunnel-vision urge to focus only on the evidence needed for trial. The McDowell case breathes new life into the Daubert challenge in the context of medical malpractice cases and sets a framework for the successful elimination of unreliable causation medical testimony in delayed diagnosis and treatment cases. With adequate preparation, knowledge of the literature and the law, and a methodical approach, savvy defense lawyers will find Daubert an invaluable tool in the defense of delayed diagnosis and treatment cases.

Victoria M. Davis is a senior associate with the law firm of Alston & Bird, LLP. She focuses her practice on products liability, toxic tort and complex medical malpractice defense. Ms. Davis, along with Dow N. Kirkpatrick and Cari K. Dawson of Alston & Bird, drafted the successful Daubert motion and brief that resulted in the exclusion of all of the plaintiff's experts by the Honorable J. Owen Forrester of the Northern District of Georgia, which was affirmed by the Eleventh Circuit in McDowell v. Brown, 392 F.3d 1283, 1288 n. 6, 1294 n.9 (11th Cir. 2004). Brian R. Stimson is an associate with Alston & Bird's Litigation and Trial Practice group.

The McDowell case discussed in the first part of this article presented the question of “whether it is so if an expert says it is so.” See Viterbo v. Dow Chem. Co. , 826 F.2d 420, 421 (5th Cir. 1987). Daubert and its progeny answered in the negative and established that an expert may not present a bare causation conclusion to the jury when that expert has no scientific basis for that conclusion or for any of the predicate inferences leading up to it. The McDowell claim failed because a physician's personal clinical experience, sometimes called anecdotal experience, is simply not a proper scientific basis for causation opinion testimony.

The Goal of Daubert

“The goal of Daubert … has been to bring more rigorous scientific study into the expression of legal opinions offered in court by scientific and medical professionals.” Allen v. Pa. Eng'g Corp. , 102 F.3d 194, 198 (5th Cir. 1996). Science, like law, requires that conclusions regarding disease causation be founded on evidence, rather than speculation or conjecture. In science, whether or not a particular act or omission caused an injury is not a matter of opinion or argument; it is a biological fact that can be ascertained with research and data. Similarly in law, whether an additional “delay in treatment” proximately caused a plaintiff's injury is not a matter for speculation or legal argument, but a matter of fact to be determined from admissible evidence by the aptly named “finder of fact.” The McDowell case illustrates that in the absence of reliable scientific opinion evidence, based on more than unwarranted inferences from isolated personal experiences, the matter must be taken from the jury and summary judgment granted to the defendant.

Relevant personal experience with a disease process is the equivalent of a case report, which cannot establish a causal link when scrutinized under the rigors of Daubert. A case report is a description of clinical events involving one or a few individuals that is published in a medical journal; “[It] reports unusual or new disease presentations or suspected associations between two diseases, effects of medication, or external causes of diseases.” Reference Manual on Scientific Evidence at 474-75 (Fed. Judicial Ctr. 2d ed. 2004), available at http://air.fjc.gov.. (emphasis added). When the development of a disease is evaluated in a collection of patients with a common experience or exposure, a report on the group in the literature is called a case series. The only real difference between a physician's personal anecdotal experience with a disease process in his or her practice and a case report or case series regarding the same disease process is that the latter is published in a medical journal.

Case Reports and Series

There are no controls or comparison groups in case reports or case series, and case series often lack information about whether the individuals evaluated are typical of the population affected by the disease or condition. See Id. Case reports and case series can at best serve to generate hypotheses; they cannot provide a reliable basis for a conclusion that a particular act or omission causes an injury. See Siharath v. Sandoz Pharms. Corp. , 131 F. Supp. 2d 1347, 1361 (N.D. Ga. 2001) (“Case reports are not reliable scientific evidence of causation, because they simply describe reported phenomena without comparison to the rate at which the phenomena occur in the general population or in a defined control group; do not isolate and exclude potentially alternative causes; and do not investigate or explain the mechanism of causation.”) aff'd, 295 F.3d 1194 (11th Cir. 2002). As a result, federal courts have uniformly rejected case reports as a foundation for reliable scientific opinion evidence regarding disease causation. See Haggerty v. Upjohn Co. , 950 F. Supp. 1160, 1164 (S.D. Fla. 1996) aff'd, 158 F.3d 588 (11th Cir. 1998); Casey v. Ohio Med. Prods , 877 F. Supp. 1380, 1385 (N.D. Cal. 1995); Jones v. United States , 933 F. Supp. 894, 898 (N.D. Cal. 1996) aff'd, 127 F.3d 1154 (9th Cir. 1997); Muzzey v. Kerr-McGee Chem. Corp. , 921 F. Supp. 511, 519 (N.D. Ill. 1996).

In the McDowell case, the plaintiff's experts effectively conceded that simply by chance alone, some patients who develop spinal epidural abscesses will develop permanent neurologic deficits, regardless of the timing of medical intervention. See 392 F.3d at 1299-1302. Thus, isolated case reports of neurologic injury, whether occurring in the plaintiff's experts' clinical practice or reported in the literature, were simply not a reliable foundation from which the experts could opine that a delay in treatment under the circumstances experienced by the plaintiff caused the plaintiff's neurologic injury.

While the disciplines of medicine and law both strive to reliably answer causation questions through the well-reasoned consideration of research and data, the exigencies of patient care may sometimes encourage physicians to forsake the rigorous analysis that is required in the laboratory or the courtroom for simple and intuitive answers to otherwise complex medical questions. As the U.S. District Court for the Northern District of Georgia has artfully stated:

“[D]octors every day seek to determine causes of injury and illness and make patients healthier. In their eternal quest for “the answer,” however, doctors sometimes believe that they have found a cause when they have not necessarily done so. Doctors in their day-to-day practices stumble upon coincidental occurrences and random events and … confuse association and causation. They are programmed by human nature and the rigors and necessities of their clinical practices to conclude that temporal association equals causation, or at least that it provides an adequate proxy in the chaotic and sometimes inconclusive world of medicine. This shortcut aids doctors in their clinical practices because their most important objective day-to-day is to help their patients and 'first, do no harm,' as their Hippocratic oath requires. Consequently, 'they make a leap of faith.'” Siharath, 131 F. Supp 2d at 1372.

Though medical experts instinctively may seek to employ the same methodology in the courtroom as is applied by doctors throughout the world in their clinical practices, clinical impression and differential diagnosis is not a scientific methodology that meets Daubert demands. General medical principles and anecdotal experience are not subjected to the proper intellectual rigors nor founded on peer reviewed or published studies and therefore do not constitute reliable support for expert medical opinions regarding the causation of disease processes or injuries.

A Strategy for Mounting a Daubert Causation Challenge in Delay Cases

The key to excluding causation testimony in a delayed diagnosis case is early and extensive preparation and methodical questioning during the deposition. Daubert cannot be an afterthought. A well-executed and successful Daubert attack has to be carefully choreographed from the start. If you have waited until after the expert's deposition to begin your Daubert strategy, you have already missed your cue. There simply is no substitute for early and extensive preparation.

Because a Daubert attack is part law and part science, defense experts who are already familiar with the medical literature can and should assist in this process. By the time the deposition approaches, the defense lawyer should be armed and ready to discuss virtually any piece of literature that the plaintiff's expert might throw out in support of his or her causation opinion.

From the outset, the defense lawyer should thoroughly research the medical and scientific literature for all case studies, reports, articles and empirical support of any kind relating to the disease process and the factors influencing prognosis or outcome. In many cases, there will not be sufficient peer-reviewed studies examining the differences in outcomes at various time intervals of treatment due to the ethical complications that the necessary withholding of treatment would impose. If the studies are lacking, the practitioner should attempt to establish that the expert's basis for his or her conclusions is limited to personal clinical experience and anecdotal evidence. The expert may even admit that studies that would scientifically prove his or her theory would be “impossible,” “unethical,” or “pointless” because the theory is within the realm of common knowledge, as was the case in McDowell. In any event, there should be a thorough exploration of the expert's own personal experience in diagnosing and treating the condition, including the various characteristics of his or her patient population.

In the alternative, if studies do exist that purportedly support the plaintiff's expert's opinion that a delay caused an injury, then those studies must be distinguished factually or shown to be unreliable due to flaws in the methodology of the studies themselves. For example, where possible you should seek to establish that the supporting literature is merely a collection of reported case studies or a case series. In addition, you should explore the various characteristics of the subject patients in those studies and establish all known factual differences between the study subjects and the plaintiff, with specific attention to any differences in severity and duration of the condition at the critical intervals. If you have done your homework, then you will be more conversant with respect to these studies than even the expert. Moreover, if you can establish that the expert really is not all that familiar with the details, methodology or conclusions of the study, then you will have a persuasive argument for excluding the expert's reliance on the study altogether.

Similarly, it is crucial that the defense lawyer be equally familiar with the language of Daubert and its progeny. It takes more than a passing understanding of the case's holding to use the principles effectively. Too often, busy trial lawyers wait until it is time to draft the brief before they even read and begin to understand the case law, and as a result they miss a wonderful opportunity to commit the expert to those golden terms and phrases such as “leap of faith,” “case reports,” “medical logic” and “presumably accepted” that are sprinkled throughout the case law and which can doom a plaintiff's expert's causation testimony.

Questions to Ask

Finally, once armed with working knowledge of both the medical literature and the language of the legal opinions, a successful Daubert strategy requires detailed and methodical questioning of the expert at the deposition. The expert should be pinned down, if possible, on any difference in prognosis or outcome that diagnosis and treatment at various intervals would make, and the bases for such opinions. As to the bases for the opinions, if the expert will admit that the “earlier the better” theory is so basic, common or axiomatic as to be ordinarily appreciated and understood by laypersons, you may be able to exclude the expert opinion on relevance grounds by showing that it does not aid the trier of fact as a true “expert” opinion. The defense lawyer also should strive to establish the unpredictable nature of the condition's prognosis, regardless of the alleged delay in diagnosis and treatment, and ferret out any speculation as a basis for the theory.

There are a host of “must ask” questions that should come to mind as you prepare your examination, including variations of the following, tailored to the specifics of your case:

• What empirical evidence exists in support of the opinion?
• Has the theory been tested? Can the theory be tested?
• What is the potential error rate in the theory as shown by testing?
• Does the theory have general acceptance in the community?
• What are the studies on which the expert bases his opinion?
• Were the studies merely a retroactive review of case reports versus prospective, randomized, controlled and blinded studies?
• How large was the sampling for the study?
• How old is the study and is it still valid?
• Where is the theory published in the peer-reviewed literature?
• Was the scientific method followed in the study?
• What were the circumstances of the studies?
• Can you distinguish the subjects of these studies from plaintiff's case?
• Did the studies involve patients with different characteristics, different rates of progression, different duration or severity, or different signs or symptoms?
• Did the studies account for delays at relevant intervals? For example, did they measure the difference in outcome after 1 hour, 4 hours, 24 hours, 72 hours, etc?
• Can the expert point to any studies showing incremental worsening of outcome correlated with an incremental passage of time to support the “earlier, the better” theory?
• Is the condition reversible or treatable and if so when is absolute last point of salvageability? How do you know?
• Are there some cases that are not salvageable, reversible, treatable?
• Are there gradations in the level of injury and if so how are they affected by the passage of time?
• Is there a scientific basis for predicting the extent of recovery based on the hour or day that treatment is rendered?
• What other factors are predictive of a good prognosis?
• What was the expected prognosis for this patient? Was this patient's prognosis better than expected? Worse than expected?
• Do ethical considerations of withholding treatment prevent relevant scientific studies on the issue?
• Is the theory based merely on the expert's personal observation of patients, clinical experience, or anecdotal evidence?
• Is the opinion based merely on medical logic or common sense?
• Is it something that is common knowledge or presumed by the general public?

Conclusion

Above all, abandon the notion that Daubert principles are “too academic” to explore at the plaintiff's expert's deposition, and resist the tunnel-vision urge to focus only on the evidence needed for trial. The McDowell case breathes new life into the Daubert challenge in the context of medical malpractice cases and sets a framework for the successful elimination of unreliable causation medical testimony in delayed diagnosis and treatment cases. With adequate preparation, knowledge of the literature and the law, and a methodical approach, savvy defense lawyers will find Daubert an invaluable tool in the defense of delayed diagnosis and treatment cases.

Victoria M. Davis is a senior associate with the law firm of Alston & Bird, LLP. She focuses her practice on products liability, toxic tort and complex medical malpractice defense. Ms. Davis, along with Dow N. Kirkpatrick and Cari K. Dawson of Alston & Bird, drafted the successful Daubert motion and brief that resulted in the exclusion of all of the plaintiff's experts by the Honorable J. Owen Forrester of the Northern District of Georgia, which was affirmed by the Eleventh Circuit in McDowell v. Brown , 392 F.3d 1283, 1288 n. 6, 1294 n.9 (11th Cir. 2004). Brian R. Stimson is an associate with Alston & Bird's Litigation and Trial Practice group.