The new order in health care delivery raises major obstacles to the continued primacy of internal medicine in the care of patients with acute and chronic illness. One challenge for internists is to show managed care organizations how internists provide more appropriate and more effective care to adults than do family physicians. At a time when the health care system views physicians as "providers" and patients as "clients," many managed care companies believe that the breadth of family medicine suits their needs better than the depth of internal medicine.

If family medicine poses an external challenge to the role of internal medicine in providing medical care to adults, the managed care delivery system threatens to fragment relationships within internal medicine itself. Thus, as more of the referral base of internal medicine subspecialists becomes eroded by health maintenance organizations, the issue of when and how subspecialists should be involved in care has been pushed to the forefront. The traditional role of the general internist has been further fragmented by the introduction of the "hospitalist," who assumes the responsibility of providing inpatient care in the interest of clinical efficiency and cost-effectiveness. Replacing the primary caregiver-the general internist-at a time when the patient is most vulnerable is again a threat to the role of the internist as the principal physician for adult patients in all settings.

Historical Perspective

To consider the future of internal medicine, it is useful to look at how the specialty has developed over the past century [1, 2]. The term internal medicine was introduced in the 1880s in Germany to describe a discipline that had special "scientific" knowledge of organ pathophysiology, a knowledge that remains central to the discipline today. In the United States, internal medicine initially developed as a consultative specialty with a strong biomedical focus. The identity of internal medicine was more firmly established when the American Board of Internal Medicine was created and certification as a specialist became possible. After World War II, internal medicine as a whole and its subspecialties in particular grew exponentially, fueled in part by the availability of generous funding from the National Institutes of Health for biomedical research. Despite the trend toward subspecialty medicine during the period from 1950 to 1970, most trainees who were not heading for academic positions practiced internal medicine as a comprehensive specialty, often with additional training in an organ-based specialty but without subspecialty certification.

In the early 1970s, some academic centers began forming divisions of general internal medicine within their departments of medicine, perhaps partially as a response to the "new" specialty of family medicine. At this time, a gifted group of "young Turks" formed an organization for academic general internists that is now called the Society for General Internal Medicine. The Society had a new approach to teaching the skills of generalism and used clinical epidemiology, informatics, ethics, health services research, and the emerging techniques of the decision sciences to define their research base. These generalists carried on the proud tradition of internal medicine as the first specialty to commit to the development of knowledge in the diagnosis and treatment of various diseases. Perhaps even more important have been their contributions to the development of innovative educational programs for medical students and residents and their emphasis on the preventive and psychosocial aspects of clinical practice.

Because of the louder voice of generalists in departments of internal medicine, the number of trainees who choose general medicine as a career has increased to the extent that most physicians who are seeking specialist training are entering this discipline (Whitcomb M, Association of American Medical Colleges. Personal communication). Divisions of general medicine have grown in almost all departments of medicine, populating themselves with enthusiastic role models, including generalist internists who now occupy faculty chairs at distinguished research universities.

The academic internists persuasively argue that complicated medical problems rarely fit neatly into the expertise of a single subspecialty and that referrals to multiple subspecialists may contribute to fragmentation of care. Continuity and integration of care are the core of internal medicine and bolster the specialty in its role as the comprehensive adult medical specialty. Thus, in the past century, internal medicine has moved from the Oslerian model of an elite consultative specialty to one with strengths in both general and subspecialty medicine. Internists continue to constitute a majority of specialists in adult medicine, and their numbers continue to grow even as the marketplace changes. A similar recognition of the need for general internists to coordinate adult care has occurred in the European Union countries. The European Committee on Medical Specialties [3] recently approved an obligatory base of internal medicine training to be completed in preparation for medical subspecialization.

In contrast to internal medicine, family medicine has its roots in general practice and has established standards for generalist physicians, whose practice includes medicine, pediatrics, surgery, and obstetrics. State legislatures provided the impetus for the development of the discipline of family medicine in many medical schools. The legislatures appropriately identified family physicians as the principal answer to workforce needs in underserved, particularly rural, areas. Although state medical schools now have departments of family medicine, some private, research-intensive medical schools and academic centers have largely ignored the specialty of family practice, believing that the biomedical basis of internal medicine and pediatrics is ideal for the development of knowledge about disease and its treatment.

Conflicts between Internists and Family Physicians

At a time when the complementary nature of family medicine and internal medicine should be emphasized and appreciated, an increasingly adversarial relationship between the two disciplines is arising in the tightly managed, time-constrained world of insurance-dominated practice. Managed care, with its emphasis on a high volume of 10- to 15-minute encounters, works against the very core of what makes internal medicine the productive and intellectually stimulating discipline it has been over the past century. In general, family physicians are not trained as extensively as internists in the diagnosis and treatment of the complex medical problems associated with aging and chronic illness. Family physicians should not be expected to fill this role. However, in the world of managed care, the skills of the internist may not be differentiated from those of the family physician.

Equally important in a cost-dominated environment is the need for managed care organizations to recognize the value that is added when internists serve as primary care physicians. Elderly patients and chronically ill patients with multiple problems comprise an increasing market segment. In any managed care plan, 75% of enrolled adults consider themselves healthy and require only preventive therapies, obstetric-gynecologic services, and episodic care for acute, self-limited problems. Of the remaining 25%, about half are the "worried well"; the rest are patients with serious, progressive, or chronic problems (Woll D, Cigna Health Plans. Personal communication). An internist, by training and by clinical approach, is the physician best equipped to render the most efficient and effective care for patients with chronic diseases.

The health care decisions that patients make arise from their perceived needs. Healthy young adults with families often find that family physicians meet their expectations, whereas elderly patients and patients with multisystem, chronic illnesses often believe that general internists can best meet their health care needs. Faced with a serious medical problem, however, most patients seek a physician who can provide the most expert care and who has the ability to address their concerns. It can be argued that internists have always filled this role and that they continue to be better able to function across the continuum of primary care to tertiary care than are family physicians.

Some managed care organizations seem to believe that family physicians provide a broader spectrum of care to adults and children and are more facile in procedural skills than general internists. Indeed, family physicians often feel comfortable performing such procedures even though their training has not been as extensive or rigorous as that of internists. The family physician's "versatility" in performing procedures may not be in the best interest of the patient when a more accomplished physician who performs many procedures is available.

Internal Medicine Training Compared with Family Medicine Training

Training

The residency training of internists and family physicians determines the special competencies of both disciplines and underlies their differences. Compared with the residency requirements for internal medicine, those for family medicine include more intensive training in human behavior, community medicine, and health promotion. Many physician-extenders, counselors, and patient educators now have these skills as a result of the pressure from managed care systems on physicians to concentrate on providing more advanced medical input. Internal medicine training is only one element of the curriculum during a family medicine residency and amounts to a total of only 8 to 12 months of training in inpatient settings, critical care units, and medical specialties combined. Because of the additional time that family practice residents spend gaining experience in pediatrics, obstetrics and gynecology, and surgery, it is unrealistic to expect newly trained family physicians to be as well prepared as graduate internists to care for adults with medically complex diseases.

Family medicine training contrasts markedly with that of internal medicine, which emphasizes heavily the care of critically ill patients with complex medical problems and provides rigorous, extensive exposure to the subspecialties of internal medicine. Unlike family practice residents, internal medicine residents spend much of their time in medical subspecialty clinics learning to appreciate their own competencies and limitations in these areas. The management of acute and complex diseases in both outpatient and inpatient settings should therefore remain the highest priority for internists in training. Graduate internists can learn other, less complex clinical competencies after they enter private practice far more easily than family physicians can master the management of complex, multicomponent diseases after they complete their training.

Some managed care plans assert that it takes longer to "train" an internist than a family physician for their organizations' practice needs. In the long run, however, both high-quality and cost-effective care in a managed care setting is determined by the primary physician's skills in the management of chronic disease, which accounts for approximately 80% of the health care costs in the United States. Although some experience in the managed care environment is useful in the training of efficient internists, the high-volume, brief encounter milieu of many managed care settings is not conductive to the development of a thoughtful and effective physician.

Another important strength of internal medicine training is the emphasis placed on the biology of normal organ function and the pathophysiology of disease. The old adage that internists treat the disease while family physicians treat the whole patient is, of course, untrue. Humanism and compassion are as much a part of internal medicine as they are of family medicine; internists, after all, are no more and no less human than anyone else. At the same time, an internist's depth of knowledge about pathophysiology and organ function makes an enormous contribution to his or her ability to recognize disease early and to institute rational diagnostic and treatment plans. A correct and timely diagnosis and an effective, efficient, and integrated approach to management are still crucial components of compassionate care.

Student Interest

Student interest in both family medicine and internal medicine has grown in recent years as the need for generalists in the health care marketplace has increased. Despite a decrease in Match results in the early 1990s, the number of medical school graduates who chose internal medicine increased by 5.1% in 1997, compared with a 2.8% increase in the number of students who chose family medicine (National Intern Matching Program, 1997 results). Highly motivated, capable physicians are entering both fields. Those who choose family medicine are attracted to the wide practice spectrum available to them and may be more prepared to live with the uncertainty inherent in their practice than are internists, who tend to seek early resolution of problems.

Internal medicine attracts the best and the brightest. It is seen as a field that blends compassionate care with rigorous scientific inquiry and the satisfaction of knowing the mechanisms that underlie many disease processes. Such in-depth knowledge about adult illness is neither necessary nor appropriate for the broad practice of a family physician; unfortunately, this depth of knowledge is also increasingly viewed as irrelevant for the brief encounters of the ambulatory care setting.

Present and Future Practice Patterns

The American Board of Internal Medicine and the American Board of Family Practice, as well as other leadership organizations in internal medicine and family medicine, have attempted to define the special competencies and complementary practice patterns of the specialties [4, 5]. At the same time, Saultz [6] has pointed out that many physicians "overestimate the similarity in the content of the practices of general internists and family physicians." Although at least 15% of the patients under the care of family physicians are younger than 21 years of age and although 25% of family physicians provide obstetric care, adult patients make up increasingly more of the practice of family physicians, particularly in urban areas. Moreover, strong financial incentives exist for generalists in managed care systems to provide care for sicker patients with complex illnesses rather than to refer such patients to subspecialists. These dynamics are placing an increased strain on the health care system because family physicians are less capable of treating patients with complex illnesses, given the limitations of their training in that area.

As the federal government attempts to shift Medicare coverage into managed care networks, some persons will continue to seek the comprehensive care they now receive from internists and will resist volume-driven encounters. Indeed, a recent study revealed that Medicare patients perceive that their medical care is better in the fee-for-service environment than in the health maintenance organization setting [7], particularly when these patients are the most ill. In the care of the elderly, the special relationship between general internists and their internist-subspecialist colleagues is especially important in controlling cost; in particular, the general internist is a sound judge for deciding when the care of a subspecialist is needed and when it is not. All patients expect, and deserve, to receive medical care from physicians who will keep them well over a broad range of medical circumstances. Internists, family physicians, nurse practitioners, and physician assistants-all working as a team-can achieve this goal.

Conflicts within Internal Medicine

If family medicine is an external threat that influences the internist's role as the principal source of care for adults, a major internal threat is continued fragmentation within internal medicine itself. Internal medicine has always embraced a wide range of disciplines, which has been a particular source of strength and has allowed internists to be involved in many important fields of medicine, including occupational medicine, geriatrics, and clinical pharmacology. Perhaps having various subspecialists under the umbrella of internal medicine has spared the discipline from the fragmentation that has divided general surgery into many separate branches. At the heart of this integrating force is the common core of general internal medicine training. Despite the shared values of general internists and internal medicine subspecialists, however, internal medicine subspecialists differentiate themselves from their general internist colleagues. Proceduralists and nonproceduralists now exist within such subspecialties as cardiology and gastroenterology, and the proceduralists have subgroups of proceduralists. Such fragmentation could destroy the essential continuity of internal medicine [8, 9], a prospect that is both real and disturbing.

In addition, general internists and internist-subspecialists frequently disagree about when generalist care is inappropriate and when subspecialist care should supersede. In the world of managed care, such decisions have important cost implications. Nevertheless, evidence suggests that the use of subspecialists for continuing care is appropriate when a chronic illness is dominated by a single organ dysfunction [10-12]. End-stage renal disease, chronic inflammatory bowel disease, and cancer are examples of diseases that are most effectively managed by subspecialists. Because of their internal medicine training, internist-subspecialists can effectively manage other self-limited medical problems that might arise in patients with a chronic disease. Nevertheless, lack of access to subspecialty care remains a contentious issue within the discipline as managed care seeks to lower costs by discouraging referrals to subspecialists [13].

A new and disturbing trend in health care delivery is the increasing use of hospitalists, who are rapidly gaining strength and numbers and are forming their own society [14]. The relinquishing of hospital care by general internists reflects the discontinuity and weakening of the patient–physician relationship. I believe that so many patients readily accept this separation of care because they have difficulty identifying a primary physician whom they know well and who knows them well. Even though inpatient care by primary physicians may be inefficient in some respects, it is wrong for a physician who has a trusting relationship with a patient to relinquish the patient's care to an unknown physician at a time when the patient is most vulnerable. Although many health care plans still allow the primary care physician to continue to provide care to their patients in the hospital, other plans do not. In all likelihood, the trend toward the mandatory use of hospitalists will increase.

Medical students value the role of the general internist as the complete physician, the person who is able to provide care across the spectrum of illness, from minor to life-threatening conditions. Division of general internists into outpatient and inpatient care providers is likely to decrease student interest in internal medicine. Indeed, both early and continuing care by subspecialists and inpatient care by hospitalists cloud the need for the general internist and strengthen the argument for the creation of a generic first-contact primary care physician to replace the internist.

Conclusions

Over the past century, internal medicine has evolved from an elite, biomedically based consultative specialty into a broad discipline that provides compassionate and effective care for adults of all ages and across a broad range of clinical complexity. Internal medicine continues to attract students of high achievement who find the internist's professional life to be one of intellectual excitement firmly based in the science of medicine and of deep personal and human satisfaction. Managed care organizations increasingly focus on the health of the populations they serve, hoping to promote wellness and forestall illness. Internists are particularly well equipped for this effort. Moreover, the well become sick and the U.S. population is aging. In this new world of health care delivery, the internist is best able to provide comprehensive, cost-effective care to adults as they grow old and become ill.

The recent thrust has been to increase the number of physicians in the primary care disciplines, including internal medicine, pediatrics, and family medicine. With the obvious success of the market-place in fostering generalist physicians, it is now time for internal medicine to strengthen its identity as the specialty for comprehensive adult medicine by stressing continuity of care from the ambulatory setting to the critical care unit and from health through chronic, severe, complex illness to the end of life. Family medicine is working hard to show students and the public that family physicians are equal to internists in providing health care for adults. Advocacy for family physicians has resonated well within the health care delivery system, and the challenge for internal medicine is to show that adult care by internists not only leads to outcomes of the highest quality but is also cost-effective. Internal medicine can meet this challenge, but to do so, the discipline must rediscover the common ground between the general internist and the internist-subspecialist and must find ways to blunt the discontinuity of care inherent in the hospitalist system. This is a tall order that must be filled if internal medicine is to remain the vibrant specialty it has been, bringing patients and the health care system the many strengths the discipline has to offer.