On the plus side, careful analysis of the concept of medical futility has produced several crucial insights that have immediate practical application. Medical futility must be understood as referring to both the probability and the desirability of attaining a particular diagnostic, therapeutic, or palliative goal [2-4]. Practitioners must be alert to both dimensions in dealing with patients, colleagues, students, and families.

On the minus side, analysis of the concept has failed to produce a consensus about how it should be defined or used. Many analysts who have gone to the plate and taken mighty swings at defining futility find themselves disagreeing about the soundness of probability estimates of success expected now or in the future from particular treatments [5-7], about which persons should be involved in estimating the chance for success [4, 8], about the value that should be assigned to attaining particular goals for particular patients [1, 4, 8, 9], and about how to implement policies that invoke medical futility [1, 8].

An assessment of the struggle to define and implement a concept that carries as much moral baggage as medical futility runs the risk of seeming, well, futile. The disputants are far apart in their thinking.

When keening their loudest, proponents of the utility of futility (aptly described as futilitarians [2-6]) foresee nothing less than the demise of the profession of medicine if physicians continue to provide care that is futile. According to this group, professional integrity requires that physicians know and inform their patients that evidence, expertise, and clinical experience have shown certain medical interventions in certain situations to be pointless, useless, and meaningless. The critics retort that integrating medical futility into clinical practice is immoral at best because physicians have no grounds for imposing their personal values about what ends are worth pursuing at what odds [1, 4, 9]. Even worse, according to these critics, such decisions are misleading because statistical information about classes of patients frequently cannot be used to forecast the outcome for a particular patient.

It is hard not to take sides in such a spirited debate—especially when the pages of prominent journals remain open to publishing yet one more round—but refraining is the right thing to do. One lesson quickly learned by anyone who engages in conceptual analysis of a bioethical problem is that a concept should not be expected to bear more weight than it can reasonably sustain. I am afraid that this has happened in the case of medical futility.

Schneiderman and coworkers [4] and other proponents of the utility of medical futility are correct in arguing (as they do elsewhere in this issue) that information about the likelihood of producing various treatment outcomes can and must be of central importance in the practice of medicine. It is possible, as Rubenfeld and Crawford show in this issue [5], to use retrospective analysis of case histories to identify predictors for death and trends in mortality that are associated with the treatments given to various categories of patients. Policymakers, third-party payers, and consumers and providers of health care lament that, in the practice of medicine, far too little rests on evidence-based outcome standards [10]. This lament has imposed a duty to collect and use information about treatment outcomes, especially death, the inability to exist without technological life support in intensive care units, and the inability to return to consciousness. These end points are all key elements of any plausible definition of medical futility [2-4, 6].

The problem that confronts futilitarians is not one of definition. Although gray areas always exist, the medical profession is free to be somewhat restrictive and arbitrary about odds and ends when publicly setting the boundaries for futility. The profession can always count on courts, legislatures, patient advocacy groups, and the media to quickly challenge any limit that appears to be overly restrictive or arbitrary. The problem that faces those who put their hope in medical futility as a way to rationalize the provision of care is not the lack of consensus about a definition but the absence of trust between physician and patient when it comes to weighing those odds and those ends.

Without trust, outcome-based medicine is doomed. If a patient or a family is to trust the physician's pronouncement that mechanical ventilation should not be continued beyond a fixed number of days after bone marrow transplantation [5, 6] or that a child born with anencephaly will not recover no matter what is done [11], they must trust the physician. Numbers alone, even grim ones derived from thousands of cases and years of experience, will not suffice. And trust between physician and patient is in jeopardy today.

Although the sources of distrust between physicians and patients are many and varied, one major source is medicine's continued inability to break down the barriers posed by race, ethnicity, religion, and economic disparity, as suggested in this issue and elsewhere [12, 13]. When patients do not trust what physicians say—not for want of evidence about prognosis and benefit but because patients do not believe that physicians are their advocates, because physicians do things that are racially or culturally insensitive, because physicians show little or no interest in their patients' religious beliefs [13], or because physicians simply seem to be too distant and removed from the living experience of their patients—the prognosis for trust is poor. When patients have no health insurance or cannot meet the requirements for copayment, they have reason to doubt a physician who says that nothing else can be done. When the prognosis for trust is poor, so are the prospects for guiding treatment by means of data about medical futility.

Efforts to contain cost that force the physician at the bedside to consider patient needs as well as the fiscal consequences of provision of care also corrode trust. If physicians are not seen as zealous advocates for those in their care, a certain degree of skepticism will attend any pronouncement of medical futility [14, 15]. Organizational and payment schemes that threaten advocacy at the bedside undermine the willingness of patients and families to trust statements that physicians make about the odds involved in achieving certain ends [16].

Futilitarians are right to urge that the medical profession should pay more attention to outcomes and use this information to guide the care provided to patients. However, they are wrong to pin all of their hopes on finding an explication of medical futility that will win the day. Whether medical futility becomes a more central part of the practice of medicine hinges on what medicine does to cement trust with those in its care. The greater the trust between physician and patient in the United States, the more willing patients will be to refrain from pursuing long odds to achieve bad ends.