Preface to the Fourth 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 instead of an alien discipline. A book that effectively provides medical perspective to biostatistics is clearly needed. To describe its focus, this book is titled Medical Biostatistics, where prefix “medical” not only precludes fishes and plants that a purist might include under the genre of “bio”statistics but also helps us to emphasize that ‘Medical + Bio’ component is dominant in this book over the ‘statistics’ component. The text fosters the thought that medicine has to be individualized yet participatory, and tries to develop pathways that can achieve this through biostatistical thinking.
Variation is an essential and perhaps the most enjoyable aspect of life. But the 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 empirical 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. We have tried to demonstrate that biostatistics is not just statistics applied to medicine and health sciences but is two steps further: providing useful tools to manage some aspects of medical uncertainties. This orientation does not stop at aleatory uncertainties but goes beyond to epistemic uncertainties as well so that all data-based uncertainties are comprehensively addressed. Among unique contribution of the book toward medicalizing biostatistics are a full chapter on sources of medical uncertainties, another on quality of investigations, also one on statistical fallacies, and an extensive debate on statistical versus medical significance. There are several other original contributions as listed in Chapter 1.
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. After this book, this audience hopefully would not complain that biostatistics methods have not been explained in an understandable way and made available to meet their need.
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. However, the sequence of chapters may not look natural to statisticians because their thoughts follow mathematical continuum. Medical and health professionals, whose biostatistics needs are problem solving, may find our sequence very natural. The contents surely follow a distinct structural divergence from a conventional biostatistics book.
The boundary between epidemiology methods and biostatistics is thin, if at all. This book 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 setups. Emphasis is on the concepts and interpretation of the methods rather than on theory or intricacies. In fact, theoretical development is intentionally de-emphasized and applications increasingly emphasized. A large number of real-life examples are included that illustrate the methods and explain the medical meaning of the results. Many statistical concepts are repeatedly explained in different contexts keeping the requirement of the target audience in mind.
In the process of projecting biostatistics as a medical discipline, while it is imperative that less emphasis is placed on mathematical aspects, the essential algebra 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 an Appendix of this book. This now uses R in this edition in place of SPSS in earlier editions. The text is thoroughly revised to provide more robust account of biostatistical applications that can provide more credible results.
The book 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 a two-semester biostatistics course for medical and health science students. On demand of those who want to adopt this as a text for courses, this edition includes exercises at the end of each chapter and brief solution of the selected exercises at the end of the book.
We are thankful to the reviewers worldwide who have examined the book microscopically and provided extremely useful suggestions for its improvement while also finding the first edition as “probably the most complete book on biostatistics”, the second edition as “almost encyclopedic in breadth”, and the third edition “seems to be an encyclopedia”. This edition incorporates most of the suggestions provided by the reviewers. Some details left out earlier have been included to provide more intelligible reading. Yet, many important techniques continue to be sidetracked in this text. This illustrates our escape from discussing complexities as the book is designed primarily for medical professionals. For similar explanation of a large number of biostatistics topics in alphabetical order, see Concise Encyclopedia of Biostatistics for Medical Professionals (CRC Press, 2016).
We are confident that the book would be found as the most comprehensive treatise on biostatistical methods. In the process, we realize we are undertaking the risk involved in including elementary and middle-level discussions in the same book. We would be happy to receive feedback from the readers.
Abhaya Indrayan
Rajeev Kumar Malhotra
