[Evolution of internal medicine and its specialties in the last decades: an outward view].

The development of the subspecialties of internal medicine in the western world is reviewed from a historical perspective, focusing on the case of the United States of America. During the last decades, changes both in society and in medicine as a whole have prompted a great dispersion of medical practice styles, not always well-defined in their contents and goals, and ranging from primary care to ultra specialization. The definition of the general internist and of the subspecialist together with the attributes of each category according to an American College of Physicians task force group are commented upon. Some of the possible reasons accounting for a decreased interest in general internal medicine during the eighties together with figures supporting a recent reversal of this trend are given. New proposals have originated in government as well as in medical circles to promote the development of general internists, conceived as physicians knowledgeable in the classic subspecialties but also skilled in clinical epidemiology, informatics, behavior medicine, decision-making, clinical economics, ethics, and problem solving. The American College of Physicians, on the other hand, considers that allowing the community-based general internists to disappear, strengthening the generalist's identity as a primary care-oriented physician who provides no subspecially care, becoming hospital-based generalists who act mainly as consultants, or becoming fully trained subspecialists who also provide primary care, are all rejectable options. These arguments illustrate the fact that even in highly developed societies a degree of indefinition remains as to the best balance between general internal medicine and its subspecialties.