Evidence-Based Medicine and the Law

U.S. courts have only just begun to figure out how to deal with clinical practice guidelines (CPGs). To date, most of the litigation about CPGs has involved claims of medical malpractice. Going forward, it is likely that CPGs will also figure prominently in suits involving coverage decisions made under health plans. The relatively few courts that have dealt with CPGs have varied widely in their treatment as evidence. In some instances, CPGs have simply been deemed inadmissible. For example, a 1995 Maryland statute enacted to encourage guidelines development provided that CPGs developed under the program it established could not be used in litigation (Md. Code Ann. [Health-Gen.] Section 19-606), a restriction that has since been removed from the legislation. In future cases, pursuant to state legislation fostering CPG development and use, some courts will admit them only for use by the defense. Even where they can be introduced by both parties to a litigation, there is a range of alternatives as to how much weight they will be given. Certainly, it will be some time before there are settled conventions for the use of CPGs and for instructing juries on the matter.

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The Importance of Federal Law

The analysis in the following section builds upon state law foundations and assumes the role of CPGs will be determined as a matter of state law. Medical malpractice has historically been a matter of state law and not subject to federal control. For that reason, federal courts have rarely been involved, except in diversity of citizenship cases, that is, where a citizen of one state sues a citizen of another state and the amount in controversy exceeds a statutory threshold, currently $75,000. In diversity cases, the U.S. Supreme Court's ruling in Erie R. R. Co. v. Tompkins (304 U.S. 64 [1938]) requires federal courts to follow the applicable state law, if there is any. In cases before them on whatever jurisdictional ground, however, federal courts largely apply their own rules of procedure. Thus, to the extent that the treatment of CPGs is regarded as an evidentiary (procedural) matter, federal courts are free to fashion rules regarding their admissibility, rules of application, weight, and so on. If, on the other hand, the use of CPGs is deemed to be substantive rather than procedural, federal courts would be bound to follow state law or, in the absence of controlling state law, to treat CPGs as they predict courts in the relevant state would if the same case were tried there. In this author's proposal for a federal program to certify CPGs, the assumption that state law would control is, for the most part, set aside.

There is ample precedent for extending federal control beyond its traditional limits through "carrot and stick" initiatives, whereby adherence to federal law, or federal standards for state law, is the statutory quid pro quo for receiving federal funds. The federal health care programs, Medicare and Medicaid, are examples of this in general. As a more concrete example, hospitals that participate in Medicare and operate an emergency department are required by the Emergency Medical Treatment and Active Labor Act (EMTALA) (42 United States Code Annotated, Section 1395dd [1985]) to provide initial assessment, advice, and treatment until the patient's condition is "stabilized," as defined in the legislation. The obligation applies whether or not the individual in question is covered under the federal program. Presumably, something similar might be undertaken in the present instance, if adequate political support for a federal CPG program could be developed. Note, however, that such a change would raise significant issues of statutory and constitutional law. The division of authority and responsibility for financing, providing, and regulating health care involves complex questions of states' rights and separation of powers. It also implicates important federal statutes, such as the McCarran-Ferguson Act (15 United States Code 1011, et seq. [1945]) and the Employee Retirement Income Security Act (ERISA) (29 United States Code 1001, et seq. [1974]). Further consideration of the role of federal law is reserved for the later discussion of the proposed certification program; the rest of this section assumes that state law controls.

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Admissibility and Weight Given to Clinical Practice Guidelines

There are various approaches state courts could take with regard to clinical practice guidelines in the context of medical malpractice litigation. The treatment of CPGs obviously will depend on the underlying legal terrain in each state. There is substantial commonality among the states with regard to their definitions of medical negligence and the evidentiary requirements for proving and defending against malpractice claims. However, there are differences among the states that, while subtle and occasionally largely semantic, may yet be quite significant. The possibilities set forth below are not mutually exclusive; a court could adopt a treatment of CPGs that combines elements of two or more of them.

As Evidence of Customary Practice. A core principle in medical malpractice litigation followed in most, but not all, cases is that the legal standard of care is set to customary practice in the relevant medical community, the so-called professional community standard. Thus, in most jurisdictions, under most circumstances, adherence to prevalent professional standards is an adequate defense to a claim of medical negligence. The most obvious possibility for the use of CPGs, then, is that a court could look to them as evidence of what is customary practice in the medical profession. A physician who practiced in conformity with a CPG would be shielded from liability to the same extent as one who could establish that she or he followed professional custom. Conversely, a physician's failure to conform to a recognized guideline could raise an inference that she or he did not perform up to the required standard; at the least, it would obligate the physician to explain why the CPG was not followed.

The main problem with treating CPGs as evidence of professional custom, however, is that in the case of a newly developed guideline, the treatment approach it calls for may differ, perhaps substantially, from prevailing practice in the profession. This is particularly likely in the case of cost-reducing guidelines that have evolved from EBM studies that conclude that the conventional practice "overtreats" the patient and wastes resources without yielding discernible or sufficient benefit in terms of better treatment outcomes. As noted above, some CPGs are developed through a consensus process, in which the treatment recommendations are an amalgam of contemporary professional belief and practice. Other CPGs are generated through a more scientific, EBM-oriented process, in which the foundation is rigorous analysis of empirical outcomes data rather than the cumulated beliefs of practitioners. If admitted as evidence in malpractice litigation, guidelines formulated in the first way described would generally serve much the same function as medical expert testimony as to customary practice. The latter type of CPGs, at least when first disseminated to the medical community, are much less likely to reflect current professional practice. Such guidelines are commonly employed in an attempt to change physician practices in order to make them more cost-effective. As a new guideline gains more currency and more adherents, it will increasingly become synonymous with customary practice. In the short run, however, it is likely to be just the opposite, a statement of what the profession at large currently does not do. Thus, so long as courts use "customary practice" to set the legal standard for acceptable practice, EBM-derived CPGs will be of limited or questionable utility in the legal system.

It is instructive to note that CPGs developed from EBM rather than through a professional consensus process differ in this regard from the more traditional Medicare utilization review (UR) protocols, which were statutorily required to be based upon "professionally developed norms of care, diagnosis, and treatment based upon typical patterns of practice" (Public Law 92-603, Section 249f, 42 United States Code, Section 1301). The requirement that Medicare's UR protocols be derived from customary professional practice, as revealed in Medicare claims data, undoubtedly was driven by political pressure from professional interests. Professors William Trail and Brad Allen (1995-96: 236-237) draw a different distinction between what they call "medical practice guidelines" and UR guidelines. They characterize the latter, pejoratively, as being concerned only with cost containment and thus having no relevance to quality of care debates. Havighurst (1990: 778, n.3, citing Lewin and Erickson 1989: 3) acknowledges a similar distinction between "pathway" (quality) guidelines and "boundary" (payment) guidelines: "Boundary guidelines are used by payers to define the range of practice options within which physicians could act without incurring financial or other sanctions. Pathway guidelines are employed primarily by providers and serve as a beacon for clinical practice and a standard around which practice patterns should converge."

As Evidence of a "Respectable Minority" Approach. A number of states recognize it as a malpractice defense that the defendant acted in accordance with the custom of at least a "respectable minority," or recognized subgroup, of the relevant profession, even though his or her actions were at odds with mainstream professional practice (Furrow et al. 1997: 198-202). In such a state, a relatively new guideline, although it has not yet been adopted widely enough to be reflective of "mainstream" practice, might be sufficiently well accepted to qualify under the "respectable minority" doctrine. Use of this defense would seem apt where the issuer of the guideline was a well-established professional society, such as the American College of Obstetrics and Gynecology (ACOG). However, if the guideline were the product of an upstart or renegade group, or perhaps a team of commercial consultants working under contract with an MCO with the transparent objective of devising ways to reduce costs, it might be rejected as not representing the position of a "respectable minority" of the profession.

As Evidence of "Reasonable Prudence." Adherence to a legitimate CPG could be treated by the court as evidence of a physician's "reasonable prudence," even if it were not established that a substantial number of physicians had yet applied the guideline's approach in clinical practice. Some courts define the physician's legal obligation of due care in terms of reasonable prudence rather than adherence to professional custom. This was the approach taken in the Washington Supreme Court's controversial decision in Helling v. Carey (519 P.2d 981 [Wash. 1974]), which held that reasonable prudence, not customary professional practice, is what should be determinative in setting legal standards for medical care. In so holding, the Helling court cited Judge Learned Hand's oft-quoted declaration in The T.J. Hooper (60 F.2d 737, 740 [2d Cir. 1932]) that "in most cases reasonable prudence is in fact common prudence; but strictly it is never its measure." A court following the Helling rationale could choose to regard a physician's reasoned compliance with a legitimately developed CPG as meeting the standard of reasonable prudence.

As Evidence of "Acceptable Practice." Regardless of the number of practitioners actually following a particular treatment modality at the time, a court could choose to regard it as "acceptable practice" within the medical community if sanctioned by an appropriate and credible CPG. This approach, suggested some twenty-five years ago by Professor Joseph King (1975: 1236), would be very similar to direct application of the CPG as the applicable legal standard, which is discussed next. It is also similar in concept to the "respectable minority" doctrine, discussed above. That is, if the medical community respects a practice as having been carefully considered and found acceptable by a reputable subset of the profession, it would not be regarded as improper practice, even if relatively few clinicians had actually adopted it as of the time in question. The key to the court's recognition of the CPG as the legal standard would, in any case, be the medical profession's acceptance of the CPG as authoritative. As in the case of the respectable minority doctrine, acceptance would be affected by the reputation and influence of the body(ies) developing, endorsing, and/or adopting the CPG.

As the Legal Standard of Care (Direct Application). The most straightforward and complete acceptance of a CPG, of course, would be for a court simply to treat it as setting the applicable legal standard without going through any intermediate steps based upon professional acceptance or customary usage. Giving such direct application to CPGs would be a substantial departure from existing law and would, presumably, require legislative action (ibid.: 1235). While this is a simple route conceptually, it would be a major step politically, since detaching standard setting from professional consensus has far-reaching implications.

If a CPG were to be adopted as the legal standard, questions remain as to how that standard would be applied. Regarding the weight to be given to it, the most extreme approach would be to treat it as a per se standard. In other words, it would be conclusively, or irrebuttably, presumed that the physician was negligent if she or he didn't follow the standard and, conversely, that the care was reasonable if she or he did follow it. This is essentially the approach specified in Minnesota's practice guidelines legislation, discussed below (Minnesota Statutes, Section 62J.34[3], [1992]). A less prescriptive approach would be to treat compliance with a relevant guideline as raising a rebuttable presumption that the physician acted correctly; similarly, noncompliance would raise a rebuttable presumption that the physician acted negligently. Whichever party asserted the guideline, the opposing party could attempt to counter this presumption by appropriate evidence. This was the approach contemplated in the Health Equity and Access Reform Today (HEART) bill, proposed by Senator John Chafee (R-R.I.) and others in 1993. (S. 1770, 4025, 103d Cong., 1st sess.). Under HEART, adherence to state-developed guidelines which had been certified by the secretary of Health and Human Services would raise a rebuttable presumption of appropriate care that would be overcome only by "clear and convincing evidence," a stricter than normal evidentiary standard favoring the party complying with the guideline. The Chafee bill is significant here because, in the part just discussed, it bears a close resemblance to the proposal put forward below for a CPG certification program.

Another dimension to the adoption of a CPG as the legal standard would be whether that standard is available for use by both the plaintiff and the defendant. Recent evolution of the use of CPGs as a legal standard has favored their use only as a defense by the health care provider. Whether CPGs should be applied in such an asymmetrical manner is considered below.

Directly applying CPGs as the legal standard for medical care is an extreme recognition that seems inappropriate and unlikely at this relatively early stage of their development. Public, professional, and judicial confidence in CPGs would have to be greater than it is currently for them to be accorded this much weight by the legal system. Before such confidence could be gained, many more issues about CPGs, their auspice, development, and so on, would have to be addressed and satisfactorily resolved. Because these conditions have not been met, the American Medical Association opposes, for the present at least, direct adoption of CPGs as a legal standard and urges instead that they be used only as evidence of the customarily observed professional standard of practice and that their degree of authority be dependent upon the degree of their acceptance among medical practitioners (American Medical Association 1993: 58; Hirshfeld 1993: 323). As Richard F. Corlin, M.D., testified on behalf of the AMA (1993: 58): "At the present time, insufficient evidence exists to show that clinical practice guidelines can be developed in a manner specific enough to be introduced as an affirmative defense in medical liability litigation." It is notable that the AMA's reservation about CPGs was stated even in the context of their defensive use.

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Courts' Experience with Clinical Practice Guidelines

To date, there has been relatively little litigation using CPGs. Andrew Hyams, David Shapiro, and Troyen Brennan (1996) did an extensive computerized legal search covering the period from January of 1980 through May of 1994 and turned up only thirty-seven cases involving CPGs. This is not to say, however, that CPGs do not figure importantly in malpractice litigation. A survey of medical malpractice attorneys conducted by Hyams, Shapiro, and Brennan (1996: 292) revealed that about half of them were aware of practice guidelines and a substantial number considered guidelines in deciding whether or not to take on malpractice cases. Guidelines also influenced settlement negotiations in many instances. Thus prelitigation effects are an important part of the picture, although such effects do not show up in studies of reported cases.

In principle, although not necessarily in practice, guidelines can be used in litigation by both patient-plaintiffs and physician-defendants. A patient-plaintiff can use a CPG for inculpatory (blame-placing, or "sword") purposes by establishing that there was an applicable guideline that the defendant should have followed but did not. Conversely, a defendant can use a CPG for exculpatory (blame-relieving, or "shield") purposes by showing that he or she acted in conformity with an applicable guideline. In either case, the party asserting the guideline is asking the court to accept it as proof that the physician either did (shield use) or did not (sword use) meet the legally required standard of care.

The studies by Hyams, Shapiro, and Brennan of reported lawsuits have shown that CPGs are much more commonly used by plaintiffs and, moreover, that plaintiffs have a notably higher rate of success in litigation associated with such use. Reports of the lopsided use and effectiveness of CPGs (Felsenthal 1994) raised alarm within the medical community and reinforced other concerns, noted above, about EBM, including CPGs. To avoid chilling the progress of CPG development and adoption, professional interests and legislators have joined in a politics of accommodation that threatens to turn CPG use in courts into a "one-way street" (Hyams, Shapiro, and Brennan 1996: 304). The legitimacy and advisability of this development is addressed in the following section.

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Who Can Use Guidelines and for What Purpose?

An important question that clouds the broader consideration of how CPGs should be treated in the courts is whether both plaintiffs and defendants should be allowed to use CPGs in litigation. Responding to the concerns discussed in the preceding section about CPGs being used more often and more effectively by plaintiffs, many proponents of CPGs have successfully lobbied for laws allowing only "shield" use of guidelines by defendants, sometimes referred to as a "one-way street" approach. The earliest, and still the principal, example of this uneven application is Maine's 1990 Medical Malpractice Demonstration Project (24 Maine Revised Statutes Annotated, Sections 2971-2978), which set up a five-year experiment, starting in 1992 and subsequently renewed for another five years in 1997, authorizing physicians (and their employers) to use guidelines developed through the project as a shield while prohibiting their sword use by patient-plaintiffs (see Schanz 1993; General Accounting Office 1993). Although this was the clear intent of the legislation, some have questioned whether it will have this effect in practice. A representative of the Maine Trial Lawyers Association (MTLA), which opposed the experiment before the legislature, has predicted that Maine courts-driven by constitutional due process and equal protection concerns-will ultimately allow both sides to introduce the guidelines in malpractice litigation (MTLA 1994: 754).

Some other states, notably Minnesota, have followed Maine's lead by adopting laws providing for only defensive use of practice guidelines (Minnesota Statutes, Section 62J.34[3][a] [1992]). This was also the approach of the Clinton administration's ill-fated Health Security Act proposal (H.R. 4469, 103d Cong., 2d sess., 1994: 441) and several other federal health care reform initiatives of the mid-1990s. Florida initiated a guidelines demonstration project in 1996, roughly similar to that of Maine but limited to cesarean deliveries, the most common surgical procedure in Florida hospitals (Florida Statutes, Section 408.02[9]). The Florida legislation contemplates use of guidelines as a liability shield, although it doesn't expressly limit their use to the defense.

What has been the experience under these one-sided statutory schemes? Maine, with the oldest, most fully articulated program, would seem the most likely to have data to evaluate. In fact, there apparently has been only one use of the guidelines in a litigation context since Maine's experiment began in January of 1992. T. Rosser Matthews (1999: 300) observes that there was only one claim on record (as of December 1997) in which a physician asserted compliance with an approved guideline as an affirmative defense. Earlier reports of the Maine experiment have noted no constitutional challenges to the program's asymmetry (MTLA 1994: 753; General Accounting Office 1993: 19).

The paucity of malpractice litigation in Maine since the institution of the state's CPG experiment is partly due to the fact that the same law that authorized it also mandated prelitigation screening and mediation panels. These panels are charged to "identify claims of professional negligence that merit compensation and to encourage early resolution of these claims prior to commencement of a lawsuit" and "encourage early withdrawal or dismissal of nonmeritorious claims" (24 Maine Revised Statutes Annotated, Section 2851[1][a][b]). In performing its review, a screening panel is required to determine if "the defendant complied with an applicable parameter or protocol establishing the applicable standard of care" (ibid., Section 2855[1][a-1]).

Other evidence of the program's impact, such as a reduction of health care costs reflecting a lesser incidence of defensive medical practice, is also inconclusive, although it has been reported that doctors are performing fewer medical procedures prompted by legal considerations (MTLA 1994: 753). Likewise, the effect of the demonstration project on malpractice insurance premiums is uncertain. In 1994 the state's superintendent of insurance estimated that the experiment would yield a 0.5 percent savings in malpractice premiums (ibid.). More recently, however, the Bureau of Insurance reported that it cannot distinguish the impact of the experiment from other factors affecting medical professional liability claim costs and premiums (Matthews 1999: 300). The experiment was extended for another five years in 1997. However, in a small state like Maine, with relatively few malpractice suits, it may take longer than that to gain enough data to fully assess the program's effectiveness. In fact, the program may never be able to prove a reduction in the cost of medical care or of malpractice litigation (MTLA 1994: 754). Doctors in the four specialties originally targeted by the legislation—anesthesiology, emergency medicine, obstetrics and gynecology, and radiology—have been supportive of the project. However, other specialties did not take advantage of a 1993 legislative amendment to expand the project into their areas of practice (Chapter 477 of Maine Revised Statutes Annotated; MTLA 1994: 753).

This uneven application of CPGs has come about as a political barter, with legislators assuring physicians, in effect, that if they will support the development and adoption of guidelines, those guidelines cannot be turned against them in litigation (General Accounting Office 1993: 26-27). It is not clear that such protection is needed to jumpstart the guidelines movement. The potential benefits of and practical pressures for expanded use of CPGs are so strong and widespread, as are the pressures for managed care generally, that physicians might not be able to resist them in any event. Still, political deals were struck to foster the development of guidelines meant to discourage the defensive practice of medicine (Shuman 1997: 105). Thus, in a number of states that have legislation providing for CPGs, the laws are structured largely for the protection of providers.

Should the use of CPGs be a "two-way street," with this form of evidence available equally to both parties? The answer would appear clearly to be "yes." In virtually every other context evidence that is seen as legitimate and admissible by the court is allowed on an equal basis to both parties. Giving providers assurance that guidelines can be used only in their favor may be an important step toward gaining their support; but allowing such one-sided use of evidence in a court of law raises disturbing questions of fairness and of validity under the U.S. Constitution's Fifth and Fourteenth Amendments' due process and equal protection mandates, and under state constitutional principles as well (see Begel 1995: 93-97; Mehlman 1990: 378; but see Hirshfeld 1991: 2889-2890).

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The Problem of Conflicting Guidelines

Supporting the early enthusiasm for CPGs was the notion that they would ease the job of the courts in deciding medical malpractice cases (Brennan 1991: 73). As mentioned above, getting at "the truth" in these cases has traditionally involved a "battle of the experts," with professionals on both sides offering opposing testimony as to the applicable standard of care and the lay jury left scratching its collective head over which of the two (or more) experts to believe. If there were a definitive guideline, some theorists reasoned, the courts could simply treat that guideline as setting the applicable standard of care. Even with the CPG supplying the legal standard, there would still be challenging work for the jury. For instance, there could be difficult factual questions as to (a) whether the CPG proffered was appropriate to the case being litigated; (b) if so, whether the defendant provider had complied adequately with the CPG; (c) whether, if there was noncompliance with an applicable guideline, the plaintiff's harm resulted from that noncompliance; and so forth. Nonetheless, having a single, definitive point of reference to fix the appropriate standard of care would greatly simplify the judicial process, largely by avoiding the traditional battle of the experts on that critical issue.

Having a single authoritative guideline for each medical condition is not likely to be, however. For one thing, achieving such unanimity would require designating some entity, presumably a governmental agency, as the sole arbiter of what is acceptable medical practice. That is practically and politically inconceivable; the commitment to pluralism and competition is too deeply ingrained in the American spirit, to say nothing of pervasive distrust of government processes. Moreover, some health policy experts have argued for encouraging competing practice guidelines as a way of contractually reforming the health care system (Havighurst 1991: 93).

Accepting that there will almost certainly be multiple guidelines for many conditions, courts will have to engage in a process of deciding, when guidelines conflict on a material point, which one to treat as authoritative, or more authoritative. This promises to be a daunting task. As shown by the breast cancer screening example presented earlier in this article, knowledgeable, respected professional groups can, and often do, come down on opposite sides on a particular treatment issue. What should be done when that happens? When two (or more) groups, and thus their guidelines, are of equal stature and authority, a jury could be instructed that the defendant physician acted acceptably if he or she followed either guideline. Such an instruction would closely mirror the "two schools of thought" doctrine long recognized in numerous U.S. jurisdictions (Furrow et al. 1997: 200 n. 3). It is closely related in concept and application to the "respectable minority" doctrine discussed above.

But what if the trial judge does not view the conflicting guidelines as being of roughly similar stature or authority? What if there is a significant difference between the apparent quality of the guidelines or between the auspices from which the conflicting guidelines emanate? Should the court then exclude the guideline of the lesser organization, or instruct the jury to give greater weight to the treatment recommendations of the better known or more respected organization? That hardly seems workable; arguably it even violates due process by invading the province of the jury. What is likely to happen, then, is that, assuming both guidelines meet minimum qualifications, they will both be admitted and the jury will be left to choose between them—perhaps with adequate wisdom, perhaps not. If the court regards one of the guidelines as not meeting the minimum standard for admissibility, presumably it could and would exclude it; but what criteria would it use in making that determination? If these questions seem familiar, perhaps it is because they are issues raised by the implementation of the Daubert decision, discussed by Shuman here. Surely, a means to help courts sort out the problems posed by conflicting guidelines would be a major contribution to the utility of guidelines and the willingness of courts to deal with them. A governmental certification program for clinical practice guidelines would seem to offer substantial benefits in this regard. Before proceeding to lay out such a legislative solution, however, it would be well to examine the underlying "politics" of CPGs.

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