In 2015, the National Academy of Medicine in the United States published a report on diagnostic error. The report from the committee, of which I was a member, concluded that virtually every adult American has been a victim of at least one diagnostic error, often with serious clinical consequences. Studies that followed the publication of the report estimated the number of deaths from diagnostic error in the United States to be on the order of 60,000 individuals per year.
The report investigated contributing factors to diagnostic error. One of the major difficulties identified was that the diagnostic specialty of laboratory medicine is too often left in the hands of the treating physician, without consistent or clinically valuable support from laboratory medicine specialists. This is unlike anatomic pathology and radiology, which provide diagnostic information to other specialties of medicine from individuals who have years of specialized training in their respective areas. The clinical laboratory test menu has become increasingly complex, expensive, and confusing to most physicians, especially with the introduction of much genetic information since the early 2000s. In most medical schools in the United States, and certainly in schools training nurses and other front-line health care providers, there is no course in laboratory medicine, and the laboratory medicine that is taught is usually not presented by experts who are knowledgeable about the operating parameters of clinical laboratory tests. The meanings of sensitivity, specificity, and predictive value of a positive or negative test are not part of the working knowledge of the treating physician. This is not the fault of these health care providers, but it does present a challenge to those creating curricula, about meeting current and future demands of health care practitioners. The diagnostic error committee noted that there is a substantial need for laboratory medicine education for all health care providers, beginning when they are students, as well as an increased number of specialists in laboratory medicine to help non-specialists in the selection of appropriate tests and in the interpretation of test results.
The National Academy of Medicine Committee also noted in their report that another major problem leading to diagnostic error is that treating doctors “do not know what they do not know.” Too many physicians are confident in their knowledge about laboratory testing when, in fact, they should not be. The clinical significance of the result has become far more complex than most physicians understand because so much more is known about both diseases and the technical issues relevant to the tests. It is abundantly clear that most of the diagnostic errors made by treating physicians are initially unrecognized, and many are never recognized, by either the provider or the patient, and only brought to attention if an expert becomes involved in the case.
It is much easier, especially for a first-time learner, to have the most important material in a single field presented in one scholarly work. When I was a medical student, most comprehensive textbooks in laboratory medicine, many of which still exist, were written at a level for experts in the field. It was said frequently to me as a specialist in laboratory medicine, in the years prior to the publication of the first edition of this book, that the field of laboratory medicine was unlikely to become a part of general medical education unless there was a new textbook in the field that is comprehensive yet simple for medical students, clinical laboratory scientists, and health care professionals involved in patient care, including practicing physicians.
As this textbook enters its third edition, all of the chapters continue to improve in presentation of both the material and the content. The journey from the first edition of this book to this third edition has involved a quantum leap from each previous edition to the new one. As this textbook is translated into languages that allow it to serve the global community of laboratory medicine, it is my greatest hope to continue making each new edition far better than the last.