Abstract
Most doctors have an intuitive understanding how diagnostics are affected by factors that emerge as they take a history and examine a patient. They also understand that common diseases are more likely than rare ones; but they probably don’t appreciate the science or statistics that underlie this reasoning. Part of the background is that the science is published in epidemiology textbooks and is often difficult to read. This argument is no longer tenable in the world of evidence-based medicine (EBM), as EBM requires a working knowledge of terms such as sensitivity, specificity and odds- and likelihood-ratios. The first few chapters of this book explain these terms in really easy and clear language using clinical examples, and it reads as if someone is standing in front of the reader giving a tutorial. Further, it helps the EBM learner by including a chapter on bias in clinical research. These first 64 pages, in my opinion, justify purchasing this book.
The chapter that warmed me to this book was on appropriate testing and explains why clinicians do unnecessary tests and what the ramifications of false positive and false negative tests are. In laboratory medicine, we know these effects but they are not often regaled in a book for front line clinicians.
This is the second edition of Evidence-Based Emergency Care and that is the weakness of the book because evidence grows so quickly that the contents soon become out of date…and this is particularly noticeable where diagnostics is changing rapidly such as in the field of acute coronary syndrome. Much of the book refers to imaging rather than laboratory medicine because these tests alter treatment options. Laboratory medicine tests are used mostly for monitoring rather than diagnosis and this is clearly shown for many conditions where clinical scoring systems exist. These scoring systems help to put a perspective into the debate about the place of laboratory tests in the decision-making process.
This book fills an important gap in the body of work about EBM in the emergency department and is a comprehensive and well-written primer to the topic. It will be useful for all colleagues who are attempting to rationalise the use of laboratory tests in their emergency department.