PREFACE This book is written for students who are preparing themselves to be public health officials and for public health officials who are willing to be students. It makes no claim to be an exhaustive treatise or a compendium of facts; it is merely a guide to the study of vital statistics, an introduction to the great world-wide science of demography a science yet in the magmatic stage, not yet crystallized. The Great War is bound to develop this science, because hereafter all the nations of the earth must know each other better, and this knowledge, in order to be usable, must be condensed into statistical forms. Specifically the book tells what statistics are and what they are not; it shows how to express vital facts by figures, how to tabulate them and how to display them by diagrams; it shows how to compute birth-rates and death-rates and how to analyze a death-rate; it shows how to adjust and standardize death-rates and how to make life tables; it emphasizes the need of using vital statistics with truth, with imagination and with power. For the convenience of school instruction, exercises and questions to incite further study are given in each chapter. Many subjects worthy of special study, however, are not even mentioned, loose ends have been left in every chapter, illustrations have been chosen as they came conveniently to hand, and the general arrangement has been informal as to its subject matter. The object in all this has been to stimulate the reader to critically analyze all vital statistics as they appear before him from day to day. Although the illustrations have been gathered in a haphazard way, an attempt has been made to set forth the elementary principles of the statistical method in a simple and orderly fashion. The author wishes to confess that he is not an authority on vital statistics, much less an authority on demography; he is merely a student of the science. He has taken the student's privilege of quoting freely from many writers to whom he wishes to render acknowledgments and thanks. In particular he desires to express his obligations and personal regards to Dr. William H. Davis, Chief Statistician for Vital Statistics, United States Bureau of the Census, who has read the entire proof of this book and given the benefit of his careful criticism. Just a personal word to the health officers of America. A new day is dawning for you. The care of the public health is becoming a distinct profession. The medical profession alone is not able to cope with it. The young men and women who are to be the executive health officers in the next generation are recognizing the need of special training, based on the principles of preventive medicine, hygiene and sanitation. Schools of public health are coming into existence and receiving warm-hearted support. The health administration of the future will be in the hands of full-time officials, who are adequately paid and protected in their tenure of office, but who in return for these advantages must be adequately trained for their work. The ability to use vital statistics in public health work is an important part of this training. Many of you have been in office for a long time, you have forgotten most of your arithmetic — not to mention algebra. You can see the new era coming and you dread the new methods founded on accurate statistical studies of accident, disease and death. There is no need of this fear. You can use statistics as well as any one, but you must study. This book has been prepared with your difficulties in mind. CAMBRIDGE, MASS. GEORGE CHANDLER WHIPPLE |