Almost immediately after whole-slide imaging for primary diagnosis received approval by the European Union's Conformité Européenne (CE marking) in March, it became a reality in Canada as well.1,2 As such, it is unlikely that the Food and Drug Administration (FDA)—with its authority over medical devices that requires whole-slide imaging system manufacturers to gain approval of their systems for their widespread use—will lag far behind Europe and Canada in approving the use of whole-slide imaging for primary diagnosis. Indeed, although nothing is certain, as the United States is now the only industrialized Western country to not have approved whole-slide imaging for primary diagnosis, it would be reasonable to expect FDA approval within the next few months.3,4
Digital pathology already has a place in teaching5,6 and research,7,8 and its uses are growing exponentially.9–12 Indeed, in both surgical pathology and cytopathology,13–15 digital pathology is poised to do no less than “redefine how pathology is practiced and the role of the pathologist.”16 Of course, substantial challenges accompany the establishment of digital pathology, including technical and workflow issues, standardization, and whole-slide imaging validation, and these are currently being addressed by the College of American Pathologists and other organizations.17–21 With tenacious cost and storage issues quickly becoming manageable, the technical path is rapidly being cleared for pathologists' use of whole-slide imaging for primary diagnosis across the United States.
As whole-slide imaging for primary diagnosis in the United States awaits FDA approval, it is important to consider the numerous and significant legal issues that surround the widespread use of digital pathology. Issues of medical malpractice and federal antikickback law have been identified22 ; however, these issues are not themselves specific to digital pathology or telemedicine generally, and, with the possible exception of complicated conflict of law issues regarding medical malpractice, they can be informed by well-settled Internet and other laws,23–25 and probably relatively easily dealt with as they arise.
THE PHYSICIAN LICENSURE PROBLEM
One legal issue, however, stands above all others surrounding digital pathology and telemedicine. The issue of physician licensure is daunting and requires substantial consideration.28–37 In fact, the issue of physician licensure is so significant that it credibly threatens to derail the promise of digital pathology altogether. And its potential solutions implicate no less than the nation's principle of federalism. And they implicate it deeply.
A SOLUTION MUST BE REALIZED SOON
No matter how difficult it may be to provide a solution to telemedicine's physician licensing issue, ignoring or delaying a solution can no longer be considered a viable option. There are strong public policy arguments that support the development of telemedicine to its fullest in the United States, including using telemedicine across state lines: telemedicine benefits patients by providing them access to health care that would otherwise not be available because of distance, it increases public knowledge about medicine, it lowers the cost of health care, it increases the speed of health care, it stimulates competition, it provides economies of scale, and it benefits struggling rural health care facilities.28,29,35,38 There are also significant ethical reasons, particularly involving the medical ethical principle of justice, to advance telemedicine (there are also ethical challenges).33 As technology has evolved, society's expectations of health care have become enhanced; popular arguments in favor of telemedicine have overwhelmed any resistance. Society is impatiently demanding telemedicine and has no stomach for long delays. And whatever solution is chosen to address telemedicine's physician licensure issue will take time to institute, so its institution must occur quickly.
POSSIBLE STATE-BASED PHYSICIAN LICENSURE SOLUTIONS
Currently, a physician must acquire a license to practice medicine in each state for which that physician's patients are located. This traditional approach worked well prior to the advent of telemedicine; however, it has rapidly become insupportable. “Any system that requires physicians to obtain licenses in each separate state poses the danger of making it too cumbersome for physicians to become separately licensed to practice in multiple states.”26 Because “[t]here are sixty-nine licensing jurisdictions in the United States, satisfying the requirements in multiple jurisdictions can be quite burdensome for a practicing physician.”39
Various state-based solutions to the physician licensure issue have therefore been proposed. “One choice is to address the practice of telemedicine as if it were merely a physician consultation occurring within a state border. Another possible choice is to ‘abbreviate' the licensing process for physicians practicing telemedicine, so that they may practice only telemedicine within that state. Further, some states have chosen to grant waivers of their licensing rules for the practice of telemedicine.”26,28 Although each of these possible solutions has some potential benefit—mainly in terms of physician compliance and bureaucratic brevity—they are ultimately “Band-Aid” or work-around solutions, and fall short. The “consultation exception,” for example, appears to contemplate only treating physicians' needs, and not pathologists' or radiologists', because it “permits out of state telemedicine physicians to consult with a locally licensed physician regarding an in-state patient. In these ‘consultation' cases, the local physician is always present.”28 And both the waiver solution and the “telemedicine only” solution are similarly problematic; they purport to hold a physician as fit to practice medicine for one purpose, but not for others. Because the world of medicine today is deeply subspecialized, a physician's “telemedicine” practice would very likely incorporate the totality of that physician's credentialed practice anyway, so that the “protective” limited nature of the “telemedicine only” license is illusory. Moreover, the “telemedicine only” solution overlooks the fact that there are other important objectives of physician licensure besides merely determining the extent of a physician's practice. “A state's goals in requiring medical licenses also include ‘protecting [the] public against [an] incompetent or unethical practitioner[,] … standardization of health personnel by specifying entry qualifications and scopes of functions[,] … [and] setting … guidelines for legal responsibility and protection of health personnel.”29 And importantly, and discussed below, with these potential solutions, the lurking issue of federalism is not so much solved as it is ignored. Permanent solutions cannot be based on exceptions, restrictions, waivers, or work-around solutions.
FEDERALISM AND STATE POLICE POWERS
The state's responsibility for its citizens' safety, for which its physician licensure requirements arise, is based on the principle of federalism, protected by the Tenth Amendment of the Constitution of the United States.29,31 The Tenth Amendment “was intended to preserve federalism and maintain the legislative power of the states by ‘preventing the national government from exceeding its more narrowly construed enumerated powers.' The Tenth Amendment states that ‘the powers not delegated to the United States by the Constitution, nor prohibited by it to the States, are reserved to the States respectively, or to the people.’29 “In light of [the Tenth Amendment] and the traditional role of states in protecting the public's health, safety, and welfare, the [United States] Supreme Court gives deference to the states in their ability to create medical license laws.”29
Under the principle of federalism, each state regulates the practice of medicine for the protection of its citizens as part of the state's police powers. The term “police powers” was coined by Chief Justice John Marshall in Brown v Maryland in 1827, 25 US (12 Wheat.) 419, 442–443 (1827), and “[a]s recently as 1991 the Supreme Court spoke in Barnes v. Glen Theatre [501 U.S. 560, 569 (1991)] of ‘the traditional police power of the States' as one which ‘we have upheld [as] a basis for legislation'; this plurality opinion of the Court defined it as ‘the authority to provide for the public health, safety, and morals.'” 40 These police powers are fundamental, basic powers that states hold and are “one of the most important concepts in American constitutional history”40,41
FEDERAL MEDICAL LICENSURE
Arguments have been put forth for the adoption of federal medical licensure as a solution to telemedicine's physician licensure problem.42 Proponents of federal medical licensure believe “[i]t is no longer realistic to expect a physician to pass state medical board examination, then practice in that state for the remainder of his or her career. State medical licensing was developed in an era of small federal government when there was ubiquitous substandard medical training; however, the federal government is now large and capable of regulating federal medical licensure, while United States medical training is homogenously meeting national standards…[and moreover,] universal healthcare coverage for all United States residents cannot realistically exist until the practice of medicine is defined at the national level.”42
However, developing a federal physician license by legislatively wresting the responsibility for licensing physicians from the state and placing it within the control of the federal government—most likely to be attempted by claiming preemption of state law via the Constitution's Commerce Clause or Spending Power29—would almost undoubtedly be a laborious, financially and politically costly, polarizing, and lengthy task; if, after many years, it was completed, the US Supreme Court would have a difficult time, in light of its long history of upholding states' police powers regarding physician licensure, in not ultimately finding it to be unconstitutional. As for the principle of federalism, were such a preemption to succeed—and given that the increase in federal power relative to state power that has occurred during the last century has already significantly eroded the principle of federalism—seizing from the states the core police power responsibility to determine who can safely be licensed to practice medicine would strike so deeply at the basis for federalism that other traditional state police powers would probably find themselves similarly at risk of being preempted by federal law. After that, the concept of federalism would be, in practice, extinct. For these reasons, both political and practical, federal physician licensure is unlikely to be a successful solution.
MUTUAL RECOGNITION: “A BETTER MOUSETRAP”
As modern ethical and legal issues involving privacy and confidentiality continue to arise in medicine, particularly with the new frontier of genetic and molecular tests and therapies,43 states are likely to place even more importance on physician licensure, and be even less willing (if that is possible) to surrender responsibility for physician licensure to the federal government. Ultimately, then, the states are going to have to step up and take charge of the issue.
If “the states do not wish to cede control to the federal government through the Commerce Clause and the Spending Clause,  they must [themselves] promulgate new regulations to ‘unlock telemedicine's vast potential.'” 29,30 The good news for the states is that they “can still build a better mousetrap. They must begin by recognizing that, today, the case for regulatory heterogeneity and the disfavoring of technologically-mediated care is quite weak. State regulators can work cooperatively with one another—witness the work of the Federation of State Medical Boards—and develop a uniform licensure and practice code. This code should adopt a standardized test for the ‘practice of medicine' and set common standards and limitations on online interactions.”31
With this “mutual recognition,” states would agree to accept physicians licensed in any of the participating states. The states would work together to harmonize their standards and produce a single set of minimum standards for physician qualification, conduct, and discipline.37,38 “A physician would obtain a license in his state of residence but would also be able to practice in any state with which his state of residence had an agreement. A physician would be subject to the laws, regulations, and professional standards of medical care in any state where he practiced.”37 This model is supported by the American Bar Association Health Law Section, which notes that “[i]f mutual recognition is adopted, state medical boards would continue issuing physician licenses and providing discipline.”37 It also recommends that, in order to minimize conflict of law issues, “each telemedicine provider agree that jurisdiction in a medical malpractice action is where the patient is located.”37
States could institute “mutual recognition” with an interstate compact, a mechanism created by the Tenth Amendment by which states coordinate with each other.44 Currently, there are more than 200 interstate compacts in existence,45 so states are familiar with them and are politically comfortable using them. Importantly, because time is of the essence, “mutual recognition” could be instituted via an interstate compact with relatively little difficulty. “Because of the similarity in licensing requirements…it would not be difficult for states to agree upon uniform minimum physician licensure requirements which states would incorporate into their laws in order to participate in the mutual recognition compact.”37
Most importantly, “mutual recognition” of state physician licensure via an interstate compact does not diminish America's principle of federalism. Indeed, it safeguards and even promotes it, for interstate compacts are federalism in action. With a “mutual recognition” interstate compact, states would appropriately maintain their police power over the licensure of physicians in their states, whereas telemedicine, including digital pathology, would be free to proceed unfettered throughout the United States. Any state that originally declines to participate in the “mutual recognition” interstate compact would soon find itself adopting it in order to provide its citizens with the nationwide benefits telemedicine offers.
Because the endeavor to create a “mutual recognition” interstate compact would require significant coordination and cooperation among the states, it is unlikely to occur until states realize a real and present danger that their police power to regulate physicians within their states is under attack. That attack would materialize via a national political drive to develop federal physician licensure. That drive, as well as the resulting threat to the states, requires only a catalyst, and the FDA's approval of whole scanned slides for primary diagnosis—with the resulting immediate and widespread demand for nationwide digital pathology services—would fulfill that requirement. When states then begin developing an interstate compact, they will, of course, need guidance, for which national medical societies, such as the College of American Pathologists, are well equipped to provide.
Digital pathology is on the horizon, and society's demand for telemedicine is robust, so a solution to telemedicine's physician licensure problem must be instituted soon. A “mutual recognition” interstate compact will require unprecedented state cooperation, but states will be strongly compelled to participate in its development because the most likely alternative—federal physician licensure—presents an unprecedented risk to federalism. The FDA's coming approval of whole-slide imaging for primary diagnosis could well be the catalyst for its institution.
Digital pathology promises to ignite issues of federalism that cannot be extinguished short of a paradigm shift in physician licensing, with implications that go far beyond pathology and implicate state police powers and the limits of federalism. Digital pathology will define 21st-century pathology. It may define 21st-century federalism as well.
The author has no relevant financial interest in the products or companies described in this article.