Preface to Third Edition
Biostatistical aspects are receiving increased emphasis in medical books, medical journals, and pharmaceutical literature, yet there is a lack of appreciation of biostatistical methods as a medical tool. This book arises from the desire to help biostatistics earn its rightful place as a medical, rather than a mathematical, subject. Medical and health professionals may then perceive biostatistics as their own discipline, instead of an alien discipline. A book that effectively focuses on the statistical aspects of medicine with a medical perspective is clearly needed. To enhance focus, this book is titled Medical Biostatistics. Prefix ‘medical’ precludes fishes and plants that a purist might include under the genre of ‘bio’statistics.
Variation is an essential, and perhaps the most enjoyable, aspect of life. But consequent uncertainties are profound. Thus, methods are needed to measure the magnitude of uncertainties and to minimize their impact on decisions. Biostatistics is the science of management of uncertainties in health and medicine. Beginning with this premise, this book provides a new orientation to the subject. This theme is kept alive throughout the text. I have tried to demonstrate that biostatistics is not just statistics applied to medicine and health sciences but is two steps further, providing tools to manage some aspects of medical uncertainties.
The primary target audiences are students, researchers, and professionals of medicine and health. These include clinicians who deal with medical uncertainties in managing patients and want to practice evidence-based medicine; research workers who design and conduct empirical investigations to advance knowledge, including research workers in pharmaceutical industry who search new regimens that are safer and more effective yet less expensive and more convenient; and health administrators who are concerned with epidemiological aspects of health and disease.
Although the text is tilted to the viewpoint of medical and health professionals, the contents are of sufficient interest to a practicing biostatistician and a student of biostatistics as well. They may find some sections very revealing, particularly the heuristic explanations provided for various statistical methods.
The boundary between epidemiology methods and biostatistics is thin, if at all. This text does not limit itself to the conventional topics of confidence intervals and tests of significance. It discusses at length study designs, measurement of health and diseases, clinimetrics, and quality control in medical setup. The text fosters the thought that medicine has to be individualized yet participatory. It tries to develop pathways that can achieve this through biostatistical thinking. Emphasis is laid on the concepts and interpretation of the methods rather than on theory or intricacies. Theoretical development is intentionally de-emphasized and applications increasingly emphasized. A large number of real-life examples are included that illustrate the method and explain the medical meaning of the results. Many statistical concepts are repeatedly explained in different contexts to bring home the point, keeping the requirement of the target audience in mind.
In the process of projecting biostatistics as a medical discipline, it is imperative to place less emphasis on mathematical aspects. But the essential algebra, which is needed to communicate and understand some statistical concepts, is not ignored. In fact, the second half of the book makes liberal use of notations. An attempt is made to strike an even balance. Medical and health professionals, who are generally not well trained in mathematics, may find the language and presentation very conducive. Equations and formulas are separately identified and manual calculations are described for the fundamentals, but the emphasis is on the use of computers for advanced calculations. Software illustrations for intricate methods are provided in Appendix to this book.
The text is fairly comprehensive and incorporates a large number of statistical concepts used in medicine and health. The contents are more than an introduction and less than an advanced treatise. References have been provided for further reading. A medical or a health professional should be able to plan and carry out an investigation by oneself on the basis of this text and intelligently seek the help of an expert biostatistician when needed. Medical laboratory professionals, scientists in basic medical sciences, epidemiologists, public health specialists, nutritionists, and others in health-related disciplines may also find this volume useful. The text is expected to provide a good understanding of the statistical concepts required to critically examine the medical literature. The material is suitable for use in preparation for professional examinations such as that for membership in the College of Physicians. The content is also broad enough to cover an undergraduate biostatistics course for medical and health science students.
I am thankful to the reviewers around the world who have examined the book microscopically and provided extremely useful suggestions for its improvement while also finding first edition as ‘probably the most complete book on biostatistics’ and second edition ‘almost encyclopedic in breadth’. This edition incorporates most of these suggestions. The second edition increased the coverage and now third edition increases the depth. Some details left out earlier have been included to provide more intelligible reading. Yet, many important techniques continue to be side-tracked in this text. This illustrates my escape from discussing complexities as the book is designed primarily for medical professionals.
The sequence of chapters may not look natural to statisticians because their thoughts follow mathematical continuum but may look natural to medical and health professionals whose biostatistics needs are for problem solving.
I am confident that the book would be found as the most comprehensive treatise on biostatistical methods. In the process, I realize I am undertaking the risk involved in including elementary- and middle-level discussions in the same book. I would be happy to receive feedback from readers.