Essentials of Biostatistics. 1. Medical uncertainties

Abstract

Health greatly differs from person to per- son and in a person from time to time. This is more prominent in children than in adults. We all know that measurements such as heart rate, hemoglobin level, birth weight and arm circumference, differ from child to child even when they are in perfect health. Variations occur not only between children but also within a child from time to time. In the face of such variations, it is not surprising that response to a stimulus such as a drug can seldom be exactly reproduced even in the same child. Uncertainties resulting from these variations are essential feature of the practice of medicine and deserve to be recognized. Biostatistics is the science of management of uncertainties in health and medicine. As we proceed, we will demonstrate how much statistical pediatric practice is due to these un-certainties, and what can be done to delineate and minimize the role of uncertainties and thus increase the efficiency of medical decisions. Our attempt in Section 1.1 is to highlight statistical aspects of day to day clinical practice. But it is in the case of medical research that many statistical subtle- ties emerge. Some of these are described in Section 1.2. Biostatistics is many times associated with community health and epidemiology. This association is indeed strong. While epidemiological perspective will be visible throughout this series, some aspects of health planning and evaluation are specifically discussed in Section 1.3. Management of un- certainties is given in Section 104. Our explanation of statistics would not be complete without describing two usages of the term. The meaning described in the preceding paragraph is valid when the term is used as a singular. More common use however is in the form of plural. Numerical information is called statistics. It is in this sense that the media use this term while talking of football statistics or income statistics and even health statistics. Biostatistics these days is a highly developed science. It is not possible to include all that is known, nor even all that is important, in this series. Nonetheless, our attempt in this series is to cover most of what. is commonly used in pediatric care and research.